\input texinfo
@c $Id: latex2e.texi 333 2015-05-12 17:12:37Z karl $
@comment %**start of header (This is for running Texinfo on a region.)
@setfilename latex2e.info
@set UPDATED May 2015
@settitle @LaTeX{}2e unofficial reference manual (@value{UPDATED})
@comment %**end of header (This is for running Texinfo on a region.)

@c latex 2.09 commands should all be present now,
@c xx but latex2e stuff is missing.
@c xx random list of a few of the missing items is at the end of this file
@c
@c xx ending a run with errors
@c xx ctan, distributions, components of TeX
@c xx classes and packages -- required, additional, useful; oberdiek; fonts
@c
@c xx merge http://mirror.ctan.org/info/latex-info/ (alt-latex-info)
@c xx merge http://mirror.ctan.org/latex2e-reference.tar.gz
@c xx merge permuted-index
@c xx merge latex-manual from savannah
@c
@c xx The typeset source2e has an index with all kernel
@c xx commands, though some are internal and shouldn't be included.
@c xx classes.dtx et al. define additional commands.
@c xx See also http://ctan.org/pkg/macros2e.

@copying
This document is an unofficial reference manual for @LaTeX{}, a
document preparation system, version of @value{UPDATED}.

This manual was originally translated from @file{LATEX.HLP} v1.0a in
the VMS Help Library.  The pre-translation version was written by
George@tie{}D. Greenwade of Sam Houston State University.  The
@LaTeX{}@tie{}2.09 version was written by Stephen Gilmore.  The
@LaTeX{}2e version was adapted from this by Torsten Martinsen.  Karl
Berry made further updates and additions, and gratefully acknowledges
using @cite{Hypertext Help with @LaTeX{}}, by Sheldon Green, and
@cite{@LaTeX{} Command Summary} (for @LaTeX{}@tie{}2.09) by
L.@tie{}Botway and C.@tie{}Biemesderfer (published by the @TeX{} Users
Group as @cite{@TeX{}niques} number 10), as reference material (no
text was directly copied).

Copyright 2007, 2008, 2009, 2010, 2011, 2012, 2013,
2014, 2015 Karl Berry.@*
Copyright 1988, 1994, 2007 Stephen Gilmore.@*
Copyright 1994, 1995, 1996 Torsten Martinsen.

Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
are preserved on all copies.

@ignore
Permission is granted to process this file through TeX and print the
results, provided the printed document carries copying permission
notice identical to this one except for the removal of this paragraph
(this paragraph not being relevant to the printed manual).
@end ignore

Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the entire
resulting derived work is distributed under the terms of a permission
notice identical to this one.

Permission is granted to copy and distribute translations of this manual
into another language, under the above conditions for modified versions.
@end copying

@dircategory TeX
@direntry
* LaTeX2e: (latex2e).              Unofficial LaTeX reference manual.
@end direntry

@tex
\global\hbadness=4444 % don't complain much
@end tex

@titlepage
@title @LaTeX{}2e: An unofficial reference manual
@subtitle @value{UPDATED}
@author @url{http://home.gna.org/latexrefman}
@page
@vskip 0pt plus 1filll
@insertcopying
@end titlepage

@shortcontents
@contents

@node Top
@top @LaTeX{}2e: An unofficial reference manual

This document is an unofficial reference manual (version of
@value{UPDATED}) for @LaTeX{}2e, a document preparation system.

@menu
* About this document::         Bug reporting, etc.
* Overview::                    What is @LaTeX{}?
* Document classes::		Some of the various classes available.
* Fonts::			Italic, bold, typewriter, etc.
* Layout::			Controlling the page layout.
* Sectioning::			How to section properly.
* Cross references::		Automatic referencing.
* Environments::		Such as enumerate & itemize.
* Line breaking::	        Influencing line breaks.
* Page breaking::	        Influencing page breaks.
* Footnotes::			How to produce footnotes.
* Definitions::			Define your own commands, etc.
* Counters::			Internal counters used by @LaTeX{}.
* Lengths::			The length commands.
* Making paragraphs::		Paragraph commands.
* Math formulas::		How to create mathematical formulas.
* Modes::			Paragraph, Math or LR modes.
* Page styles::			Various styles of page layout.
* Spaces::		        Horizontal and vertical space.
* Boxes::                       Making boxes.
* Special insertions::		Inserting reserved and special characters.
* Splitting the input::		Dealing with big files by splitting.
* Front/back matter::		Tables of contents, glossaries, indexes.
* Letters::			The @code{letter} class.
* Terminal input/output::	User interaction.
* Command line::                System-independent command-line behavior.
* Document templates::          Starter templates for various document classes.
* Concept Index::		General index.
* Command Index::           	Alphabetical list of @LaTeX{} commands.
@end menu


@node About this document
@chapter About this document

@cindex bug reporting
@cindex reporting bugs
@findex @url{http://home.gna.org/latexrefman} @r{home page}
This is an unofficial reference manual for the @LaTeX{}2e document
preparation system, which is a macro package for the @TeX{}
typesetting program (@pxref{Overview}).  This document's home page is
@url{http://home.gna.org/latexrefman}.  That page has links to the
current output in various formats, sources, mailing list archives and
subscriptions, and other infrastructure.

@cindex @LaTeX{} vs.@: @LaTeX{}2e
In this document, we will mostly just use `@LaTeX{}' rather than
`@LaTeX{}2e', since the previous version of @LaTeX{}@tie{}(2.09) was
retired many years ago.

@cindex unofficial nature of this manual
@cindex @LaTeX{} Project team
@findex @email{latexrefman-discuss@@gna.org} @r{email address}
@LaTeX{} is currently maintained by a group of volunteers
(@url{http://latex-project.org}).  The official documentation written by
the @LaTeX{} project is available from their web site.  This document is
completely unofficial and has not been reviewed by the @LaTeX{}
maintainers.  Do not send bug reports or anything else about this
document to them.  Instead, please send all comments to
@email{latexrefman-discuss@@gna.org}.

This document is a reference.  There is a vast array of other sources
of information about @LaTeX{}, at all levels.  Here are a few
introductions.

@table @url
@item http://ctan.org/pkg/latex-doc-ptr
@findex latex-doc-ptr @r{document}
Two pages of recommended references to @LaTeX{} documentation.

@item http://ctan.org/pkg/first-latex-doc
@findex first-latex-doc @r{document}
Writing your first document, with a bit of both text and math.

@item http://ctan.org/pkg/usrguide
@findex usrguide @r{official documentation}
The guide for document authors that is maintained as part of @LaTeX{};
there are plenty of others available elsewhere.

@item http://ctan.org/pkg/lshort
@findex lshort @r{document}
A short introduction to @LaTeX{}, translated to many languages.

@item http://tug.org/begin.html
Introduction to the @TeX{} system, including @LaTeX{}, with further
references.

@end table


@node Overview
@chapter Overview of @LaTeX{}

@cindex overview of @LaTeX{}
@cindex basics of @LaTeX{}
@cindex Knuth, Donald E.
@cindex Lamport, Leslie
@cindex @LaTeX{} overview

@LaTeX{} is a system for typesetting documents.  It was originally
created by Leslie Lamport and is now maintained by a group of volunteers
(@url{http://latex-project.org}).  It is widely used, particularly for
complex and technical documents, such as those involving mathematics.

@cindex macro package, @LaTeX{} as
A @LaTeX{} user writes an input file containing text along with
interspersed commands, for instance commands describing how the text
should be formatted.  It is implemented as a set of related commands
that interface with Donald@tie{}E. Knuth's @TeX{} typesetting program
(the technical term is that @LaTeX{} is a @dfn{macro package} for the
@TeX{} engine).  The user produces the output document by giving that
file to the @TeX{} engine.

The term @LaTeX{} is also sometimes used to mean the language in which
the document is marked up, that is, to mean the set of commands
available to a @LaTeX{} user.

@cindex Lamport @TeX{}
@cindex pronunciation
The name @LaTeX{} is short for ``Lamport @TeX{}''.  It is pronounced
LAH-teck or LAY-teck, or sometimes LAY-tecks.  Inside a document,
produce the logo with @code{\LaTeX}.  Where use of the logo is not
sensible, such as in plain text, write it as @samp{LaTeX}.

@menu
* Starting and ending::  The standard beginning and end of a document.
* Output files::         Files produced.
* @TeX{} engines::          Programs that implementation @LaTeX{}.
* @LaTeX{} command syntax:: General syntax of @LaTeX{} commands.
@end menu


@node Starting and ending
@section Starting and ending

@anchor{Starting & ending}@c old name
@cindex starting & ending
@cindex ending & starting
@cindex hello, world

@LaTeX{} files have a simple global structure, with a standard
starting and ending.  Here is a ``hello, world'' example:

@example
\documentclass@{article@}
\begin@{document@}
Hello, \LaTeX\ world.
\end@{document@}
@end example

@cindex document class, defined
@noindent
Here, the @samp{article} is the so-called @dfn{document class},
implemented in a file @file{article.cls}.  Any document class can be
used.  A few document classes are defined by @LaTeX{} itself, and vast
array of others are widely available.  @xref{Document classes}.

@cindex preamble, defined
You can include other @LaTeX{} commands between the
@code{\documentclass} and the @code{\begin@{document@}} commands.
This area is called the @dfn{preamble}.

The @code{\begin@{document@} ... \end@{document@}} is a so-called
@dfn{environment}; the @samp{document} environment (and no others) is
required in all @LaTeX{} documents.  @LaTeX{} provides many
environments itself, and many more are defined separately.
@xref{Environments}.

The following sections discuss how to produce PDF or other output from
a @LaTeX{} input file.


@node Output files
@section Output files

@LaTeX{} produces a main output file and at least two accessory files.
The main output file's name ends in either @file{.dvi} or @file{.pdf}.

@table @code
@item .dvi
@findex .dvi @r{file}
@findex latex @r{command}
@findex xdvi @r{command}
@findex dvips @r{command}
@findex dvipdfmx @r{command}
@findex dvitype @r{command}
If @LaTeX{} is invoked with the system command @command{latex} then it
produces a DeVice Independent file, with extension @file{.dvi}.  You
can view this file with a command such as @command{xdvi}, or convert
it to a PostScript @code{.ps} file with @command{dvips} or to a
Portable Document Format @code{.pdf} file with @command{dvipdfmx}.
The contents of the file can be dumped in human-readable form with
@command{dvitype}.  A vast array of other DVI utility programs are
available (@url{http://mirror.ctan.org/tex-archive/dviware}).

@item .pdf
@findex .pdf @r{file}
@cindex pdf@TeX{}
@findex pdflatex @r{command}
If @LaTeX{} is invoked via the system command @command{pdflatex},
among other commands (@pxref{@TeX{} engines}), then the main output is
a Portable Document Format (PDF) file.  Typically this is a
self-contained file, with all fonts and images included.

@end table

@LaTeX{} also produces at least two additional files.

@table @code
@item .log
@cindex transcript file
@cindex log file
@findex .log @r{file}
This transcript file contains summary information such as a list of
loaded packages.  It also includes diagnostic messages and perhaps
additional information for any errors.

@item .aux
@cindex auxiliary file
@findex .aux @r{file}
@cindex cross references, resolving
@cindex forward references, resolving
@cindex references, resolving forward
Auxiliary information is used by @LaTeX{} for things such as
cross references.  For example, the first time that @LaTeX{} finds a
forward reference---a cross reference to something that has not yet
appeared in the source---it will appear in the output as a doubled
question mark @code{??}.  When the referred-to spot does eventually
appear in the source then @LaTeX{} writes its location information to
this @code{.aux} file.  On the next invocation, @LaTeX{} reads the
location information from this file and uses it to resolve the
reference, replacing the double question mark with the remembered
location.

@end table

@findex .lof @r{file}
@cindex list of figures file
@findex .lot @r{file}
@cindex list of tables file
@findex .toc @r{file}
@cindex table of contents file
@cindex contents file
@LaTeX{} may produce yet more files, characterized by the filename
ending.  These include a @code{.lof} file that is used to make a list
of figures, a @code{.lot} file used to make a list of tables, and a
@code{.toc} file used to make a table of contents.  A particular class
may create others; the list is open-ended.


@node @TeX{} engines
@section @TeX{} engines

@cindex engines, @TeX{}
@cindex implementations of @TeX{}
@cindex UTF-8
@cindex Unicode input, native
@cindex TrueType fonts
@cindex OpenType fonts

@LaTeX{} is defined to be a set of commands that are run by a @TeX{}
implementation (@pxref{Overview}).  This section gives a terse
overview of the main programs.

@table @code
@item latex
@itemx pdflatex
@cindex pdf@TeX{} engine
@findex etex @r{command}
@cindex e-@TeX{}
In @TeX{} Live (@url{http://tug.org/texlive}, if @LaTeX{} is invoked
via either the system command @command{latex} or @command{pdflatex},
then the pdf@TeX{} engine is run (@url{http://ctan.org/pkg/pdftex}).
When invoked as @command{latex}, the main output is a @file{.dvi}
file; as @command{pdflatex}, the main output is a @file{.pdf} file.

pdf@TeX{} incorporates the e-@TeX{} extensions to Knuth's original
program (@url{http://ctan.org/pkg/etex}), including additional
programming features and bi-directional typesetting, and has plenty of
extensions of its own.  e-@TeX{} is available on its own as the
command @command{etex}, but this is plain @TeX{} (and produces
@file{.dvi}).  

In other @TeX{} distributions, @command{latex} may invoke e-@TeX{}
rather than pdf@TeX{}.  In any case, the e-@TeX{} extensions can be
assumed to be available in @LaTeX{}.

@item lualatex
@findex lualatex @r{command}
@cindex Lua@TeX{}
If @LaTeX{} is invoked via the system command @command{lualatex}, the
Lua@TeX{} engine is run (@url{http://ctan.org/pkg/luatex}).  This
program allows code written in the scripting language Lua
(@url{http://luatex.org}) to interact with @TeX{}'s typesetting.
Lua@TeX{} handles UTF-8 Unicode input natively, can handle OpenType
and TrueType fonts, and produces a @file{.pdf} file by default.
There is also @command{dvilualatex} to produce a @file{.dvi} file,
but this is rarely used.

@item xelatex
@findex xelatex @r{command}
@cindex Xe@TeX{}
If @LaTeX{} is invoked with the system command @command{xelatex}, the
Xe@TeX{} engine is run (@url{http://tug.org/xetex}).  Like Lua@TeX{},
Xe@TeX{} also natively supports UTF-8 Unicode and TrueType and
OpenType fonts, though the implementation is completely different,
mainly using external libraries instead of internal code.  Xe@TeX{}
produces a @file{.pdf} file as output; it does not support DVI output.

@end table

Other variants of @LaTeX{} and @TeX{} exist, e.g., to provide
additional support for Japanese and other languages ([u]p@TeX{},
@url{http://ctan.org/pkg/ptex}, @url{http://ctan.org/pkg/uptex}).


@node @LaTeX{} command syntax
@section @LaTeX{} command syntax

@cindex command syntax
@findex \ @r{character starting commands}
@findex [...] @r{for optional arguments}
@findex @{...@} @r{for required arguments}
In the @LaTeX{} input file, a command name starts with a @code{\}; the
name itself then consists of either (a)@tie{}a string of letters or
(b)@tie{}a single non-letter.

A command may be followed by zero, one, or more arguments, either
required or optional.  Required arguments are contained in curly
braces, @code{@{...@}}.  Optional arguments are contained in square
brackets, @code{[...]}.  Generally, but not universally, if the
command accepts an optional argument, it comes first, before any
required arguments.

Some commands have a @code{*} form that is related to the form without
a @code{*}, such as @code{\chapter} and @code{\chapter*}.

@LaTeX{} commands are case sensitive; neither @code{\Begin@{document@}}
nor @code{\begin@{Document@}} will work.  Most commands are lowercase,
but in any event you must enter all commands in the same case as they
are defined.

This manual describes all accepted options and @code{*}-forms for the
commands it covers (barring unintentional omissions, a.k.a.@: bugs).


@node Document classes
@chapter Document classes

@cindex document classes
@cindex classes of documents
@findex \documentclass

The document's overall class is defined with this command, which is
normally the first command in a @LaTeX{} source file.

@example
\documentclass[@var{options}]@{@var{class}@}
@end example

@findex article @r{class}
@findex report @r{class}
@findex book @r{class}
@findex letter @r{class}
@findex slides @r{class}
The following document @var{class} names are built into @LaTeX{}.
(Many other document classes are available as separate packages;
@pxref{Overview}.)

@table @code
@item article
For a journal article, a presentation, and miscellaneous general use.

@item book
Full-length books, including chapters and possibly including front
matter, such as a preface, and back matter, such as an appendix
(@pxref{Front/back matter}).

@item report
For documents of length between an @code{article} and a @code{book},
such as technical reports or theses, which may contain several chapters.

@item slides
For slide presentations---rarely used today.  In its place the
@code{beamer} package is perhaps the most prevalent (@pxref{beamer
template}).

@end table

Standard @var{options} are described in the next section.

@menu
* Document class options::   Global options.
@end menu


@node Document class options
@section Document class options

@cindex document class options
@cindex options, document class
@cindex class options
@cindex global options

You can specify so-called @dfn{global options} or @dfn{class options} to
the @code{\documentclass} command by enclosing them in square brackets.
To specify more than one @var{option}, separate them with a comma, as in:

@example
\documentclass[@var{option1},@var{option2},...]@{@var{class}@}
@end example

Here is the list of the standard class options.

@findex 10pt @r{option}
@findex 11pt @r{option}
@findex 12pt @r{option}
All of the standard classes except @code{slides} accept the following
options for selecting the typeface size (default is @code{10pt}):

@example
10pt  11pt  12pt
@end example

@findex a4paper @r{option}
@findex a5paper @r{option}
@findex b5paper @r{option}
@findex executivepaper @r{option}
@findex legalpaper @r{option}
@findex letterpaper @r{option}
All of the standard classes accept these options for selecting the paper
size (default is @code{letterpaper}):

@example
a4paper a5paper b5paper executivepaper legalpaper letterpaper
@end example

@findex draft @r{option}
@findex final @r{option}
@findex fleqn @r{option}
@findex landscape @r{option}
@findex leqno @r{option}
@findex openbib @r{option}
@findex titlepage @r{option}
@findex notitlepage @r{option}
Miscellaneous other options:

@table @code
@item draft
@itemx final
@cindex black boxes, omitting
Mark (@code{draft}) or do not mark (@code{final}) overfull boxes with a
black box in the margin; default is @code{final}.

@item fleqn
@cindex flush left equations
@cindex centered equations
@cindex equations, flush left vs.@: centered
Put displayed formulas flush left; default is centered.

@item landscape
@cindex landscape orientation
@cindex portrait orientation
Selects landscape format; default is portrait.

@item leqno
@cindex left-hand equation numbers
@cindex right-hand equation numbers
@cindex equation numbers, left vs.@: right
Put equation numbers on the left side of equations; default is the right side.

@item openbib
@cindex bibliography format, open
Use ``open'' bibliography format.

@item titlepage
@itemx notitlepage
@cindex title page, separate or run-in
Specifies whether the title page is separate; default depends on the class.
@end table

The following options are not available with the @code{slides} class.

@findex onecolumn @r{option}
@findex twocolumn @r{option}
@findex oneside @r{option}
@findex twoside @r{option}
@findex openright @r{option}
@findex openany @r{option}
@table @code
@item onecolumn
@itemx twocolumn
Typeset in one or two columns; default is @code{onecolumn}.

@item oneside
@itemx twoside
@findex \evensidemargin
@findex \oddsidemargin
Selects one- or two-sided layout; default is @code{oneside}, except
that in the @code{book} class the default is @code{twoside}.

For one-sided printing, the text is centered on the page.  For two-sided
printing, the @code{\evensidemargin} (@code{\oddsidemargin}) parameter
determines the distance on even (odd) numbered pages between the left
side of the page and the text's left margin, with @code{\oddsidemargin}
being 40% of the difference between @code{\paperwidth} and
@code{\textwidth}, and @code{\evensidemargin} is the remainder.

@item openright
@itemx openany
Determines if a chapter should start on a right-hand page; default is
@code{openright} for @code{book}, and @code{openany} for @code{report}.
@end table

@findex clock @r{option to @code{slides} class}
The @code{slides} class offers the option @code{clock} for printing
the time at the bottom of each note.

@cindex loading additional packages
@cindex packages, loading additional
@cindex additional packages, loading
@findex \usepackage
Additional packages are loaded like this:

@example
\usepackage[@var{options}]@{@var{pkg}@}
@end example

To specify more than one package, you can separate them with a comma,
as in @code{\usepackage@{@var{pkg1},@var{pkg2},...@}}, or use multiple
@code{\usepackage} commands.

@cindex global options
@cindex options, global
Any options given in the @code{\documentclass} command that are unknown
by the selected document class are passed on to the packages loaded with
@code{\usepackage}.


@node Fonts
@chapter Fonts
@anchor{Typefaces}@c old name

@cindex typefaces
@cindex fonts

Two important aspects of selecting a @dfn{font} are specifying a size
and a style.  The @LaTeX{} commands for doing this are described here.

@menu
* Font styles::                 Select roman, italics, etc.
* Font sizes::                  Select point size.
* Low-level font commands::     Select encoding, family, series, shape.
@end menu


@node Font styles
@section Font styles

@cindex font styles
@cindex typeface styles
@cindex styles of text

The following type style commands are supported by @LaTeX{}.

This first group of commands is typically used with an argument, as in
@code{\textit@{italic text@}}.  In the table below, the corresponding
command in parenthesis is the ``declaration form'', which takes no
arguments.  The scope of the declaration form lasts until the next type
style command or the end of the current group.

These commands, in both the argument form and the declaration form,
are cumulative; e.g., you can say either @code{\sffamily\bfseries} or
@code{\bfseries\sffamily} to get bold sans serif.

You can alternatively use an environment form of the declarations; for
instance, @code{\begin@{ttfamily@}...\end@{ttfamily@}}.

@findex \nocorrlist
@findex \nocorr
These font-switching commands automatically insert italic corrections
if needed.  (@xref{\/}, for the details of italic corrections.)
Specifically, they insert the italic correction unless the following
character is in the list @code{\nocorrlist}, which by default consists
of a period and a comma.  To suppress the automatic insertion of
italic correction, use @code{\nocorr} at the start or end of the
command argument, such as @code{\textit@{\nocorr text@}} or
@code{\textsc@{text \nocorr@}}.

@table @code
@item \textrm (\rmfamily)
@findex \textrm
@findex \rmfamily
Roman.

@item \textit (\itshape)
@findex \textit
@findex \itshape
Italics.

@item \emph
@findex \emph
@cindex emphasis
Emphasis (switches between @code{\textit} and @code{\textrm}).

@item \textmd (\mdseries)
@findex \textmd
@findex \mdseries
Medium weight (default).

@item \textbf (\bfseries)
@findex \textbf
@findex \bfseries
Boldface.

@item \textup (\upshape)
@findex \textup
@findex \upshape
Upright (default). The opposite of slanted.

@item \textsl (\slshape)
@findex \textsl
@findex \slshape
Slanted.

@item \textsf (\sffamily)
@findex \textsf
@findex \sffamily
Sans serif.

@item \textsc (\scshape)
@findex \textsc
@findex \scshape
Small caps.

@item \texttt (\ttfamily)
@findex \texttt
@findex \ttfamily
Typewriter.

@item \textnormal (\normalfont)
@findex \textnormal
@findex \normalfont
Main document font.

@item \mathrm
@findex \mathrm
Roman, for use in math mode.

@item \mathbf
@findex \mathbf
Boldface, for use in math mode.

@item \mathsf
@findex \mathsf
Sans serif, for use in math mode.

@item \mathtt
@findex \mathtt
Typewriter, for use in math mode.

@item \mathit
@itemx (\mit)
Italics, for use in math mode.

@item \mathnormal
@findex \mathnormal
For use in math mode, e.g. inside another type style declaration.

@item \mathcal
@findex \mathcal
`Calligraphic' letters, for use in math mode.

@end table

@findex \mathversion
@cindex math, bold
@cindex bold math
In addition, the command @code{\mathversion@{bold@}} can be used for
switching to bold letters and symbols in
formulas. @code{\mathversion@{normal@}} restores the default.

@findex \oldstylenums
@cindex numerals, old-style
@cindex old-style numerals
@cindex lining numerals
@cindex @code{textcomp} package
Finally, the command @code{\oldstylenums@{@var{numerals}@}} will
typeset so-called ``old-style'' numerals, which have differing heights
and depths (and sometimes widths) from the standard ``lining''
numerals.  @LaTeX{}'s default fonts support this, and will respect
@code{\textbf} (but not other styles; there are no italic old-style
numerals in Computer Modern).  Many other fonts have old-style
numerals also; sometimes the @code{textcomp} package must be loaded,
and sometimes package options are provided to make them the default.
FAQ entry: @url{http://www.tex.ac.uk/cgi-bin/texfaq2html?label=osf}.

@LaTeX{} also provides the following commands, which unconditionally
switch to the given style, that is, are @emph{not} cumulative.  Also,
they are used differently than the above commands: @code{@{\@var{cmd}
...@}} instead of @code{\@var{cmd}@{...@}}.  These are two unrelated
constructs.

@ftable @code
@item \bf
@cindex bold font
Switch to @b{bold face}.

@item \cal
@cindex script letters for math
@cindex calligraphic letters for math
Switch to calligraphic letters for math.

@item \em
@cindex emphasis
Emphasis (italics within roman, roman within italics).

@item \it
@cindex italic font
Italics.

@item \rm
@cindex roman font
Roman.

@item \sc
@cindex small caps font
Small caps.

@item \sf
@cindex sans serif font
Sans serif.

@item \sl
@cindex slanted font
@cindex oblique font
Slanted (oblique).

@item \tt
@cindex typewriter font
@cindex monospace font
@cindex fixed-width font
Typewriter (monospace, fixed-width).

@end ftable

Some people consider the unconditional font-switching commands, such
as @code{\tt}, obsolete and @emph{only} the cumulative commands
(@code{\texttt}) should be used.  I (Karl) do not agree.  There are
perfectly reasonable situations when an unconditional font switch is
precisely what you need to get the desired output; for one example,
@pxref{description,,@code{description}}.  Both sets of commands have
their place.


@node Font sizes
@section Font sizes
@cindex font sizes
@cindex typeface sizes
@cindex sizes of text

The following standard type size commands are supported by @LaTeX{}.
The table shows the command name and the corresponding actual font
size used (in points) with the @samp{10pt}, @samp{11pt}, and
@samp{12pt} document size options, respectively (@pxref{Document class
options}).

@findex \tiny
@findex \scriptsize
@findex \footnotesize
@findex \small
@findex \normalsize
@findex \large
@findex \Large
@findex \LARGE
@findex \huge
@findex \Huge

@multitable {@code{\normalsize} (default)} {24.88} {24.88} {24.88}
@headitem Command  @tab @code{10pt}  @tab @code{11pt}  @tab @code{12pt}
@item @code{\tiny}
@tab 5          @tab 6          @tab 6
@item @code{\scriptsize}
@tab 7          @tab 8          @tab 8
@item @code{\footnotesize}
@tab 8          @tab 9          @tab 10
@item @code{\small}
@tab 9          @tab 10         @tab 10.95
@item @code{\normalsize} (default)
@tab 10         @tab 10.95      @tab 12
@item @code{\large}
@tab 12         @tab 12         @tab 14.4
@item @code{\Large}
@tab 14.4       @tab 14.4       @tab 17.28
@item @code{\LARGE}
@tab 17.28      @tab 17.28      @tab 20.74
@item @code{\huge}
@tab 20.74      @tab 20.74      @tab 24.88
@item @code{\Huge}
@tab 24.88      @tab 24.88      @tab 24.88
@end multitable

The commands as listed here are ``declaration forms''. The scope of
the declaration form lasts until the next type style command or the
end of the current group.  You can also use the environment form of
these commands; for instance, @code{\begin@{tiny@}...\end@{tiny@}}.


@node Low-level font commands
@section Low-level font commands
@cindex low-level font commands
@cindex font commands, low-level

These commands are primarily intended for writers of macros and
packages.  The commands listed here are only a subset of the available
ones.

@table @code
@item \fontencoding@{enc@}
@findex \fontencoding
Select font encoding. Valid encodings include @code{OT1} and @code{T1}.

@item \fontfamily@{family@}
@findex \fontfamily
Select font family. Valid families include:

@itemize @bullet
@item @code{cmr}  for Computer Modern Roman
@item @code{cmss} for Computer Modern Sans Serif
@item @code{cmtt} for Computer Modern Typewriter
@end itemize

and numerous others.

@item \fontseries@{series@}
@findex \fontseries
Select font series. Valid series include:

@itemize @bullet
@item @code{m}  Medium (normal)
@item @code{b}  Bold
@item @code{c}  Condensed
@item @code{bc} Bold condensed
@item @code{bx} Bold extended
@end itemize

and various other combinations.

@item \fontshape@{shape@}
@findex \fontshape
Select font shape. Valid shapes are:

@itemize @bullet
@item @code{n}  Upright (normal)
@item @code{it} Italic
@item @code{sl} Slanted (oblique)
@item @code{sc} Small caps
@item @code{ui} Upright italics
@item @code{ol} Outline
@end itemize

The two last shapes are not available for most font families.

@item \fontsize@{size@}@{skip@}
@findex \fontsize
@findex \baselineskip
Set font size. The first parameter is the font size to switch to and
the second is the line spacing to use; this is stored in a parameter
named @code{\baselineskip}.  The unit of both parameters defaults to
pt.  The default @code{\baselineskip} for the Computer Modern typeface
is 1.2 times the @code{\fontsize}.

@findex \baselinestretch
@cindex @code{setspace} package
@cindex double spacing
The line spacing is also multiplied by the value of the
@code{\baselinestretch} parameter when the type size changes; the
default is 1.  However, the best way to ``double space'' a document,
if you should be unlucky enough to have to produce such, is to use the
@code{setspace} package; see
@url{http://www.tex.ac.uk/cgi-bin/texfaq2html?label=linespace}.

@findex \linespread
@item \linespread@{@var{factor}@}
Equivalent to
@code{\renewcommand@{\baselinestretch@}@{@var{factor}@}}, and
therefore must be followed by @code{\selectfont} to have any effect.
Best specified in the preamble, or use the @code{setspace} package, as
described just above.

@findex \selectfont
The changes made by calling the font commands described above do
not come into effect until @code{\selectfont} is called.

@item \usefont@{enc@}@{family@}@{series@}@{shape@}
@findex \usefont
The same as invoking @code{\fontencoding}, @code{\fontfamily},
@code{\fontseries} and @code{\fontshape} with the given parameters,
followed by @code{\selectfont}.

@end table


@node Layout
@chapter Layout
@cindex layout commands

Miscellaneous commands for controlling the general layout of the page.

@menu
* \onecolumn::              Use one-column layout.
* \twocolumn::              Use two-column layout.
* \flushbottom::            Make all text pages the same height.
* \raggedbottom::           Allow text pages of differing height.
* Page layout parameters::  @code{\headheight} @code{\footskip}.
@end menu


@node \onecolumn
@section @code{\onecolumn}
@findex \onecolumn
@cindex one-column output

The @code{\onecolumn} declaration starts a new page and produces
single-column output.  This is the default.


@node \twocolumn
@section @code{\twocolumn}
@findex \twocolumn
@cindex multicolumn text
@cindex two-column output

Synopsis:

@example
\twocolumn[@var{text1col}]
@end example

The @code{\twocolumn} declaration starts a new page and produces
two-column output. If the optional @var{text1col} argument is present,
it is typeset in one-column mode before the two-column typesetting
starts.

These parameters control typesetting in two-column output:

@ftable @code
@item \columnsep
The distance between columns (35pt by default).

@item \columnseprule
The width of the rule between columns; the default is 0pt, so there is no rule.

@item \columnwidth
The width of the current column; this is equal to @code{\textwidth} in
single-column text.

@end ftable

These parameters control float behavior in two-column output:

@ftable @code
@item \dbltopfraction
Maximum fraction at the top of a two-column page that may be occupied
by floats.  Default @samp{.7}, can be usefully redefined to (say)
@samp{.9} to avoid going to float pages so soon.

@item \dblfloatpagefraction
The minimum fraction of a float page that must be occupied by floats,
for a two-column float page.  Default @samp{.5}.

@item \dblfloatsep
Distance between floats at the top or bottom of a two-column float
page.  Default @samp{12pt plus2pt minus2pt} for @samp{10pt} and
@samp{11pt} documents, @samp{14pt plus2pt minus4pt} for @samp{12pt}.

@item \dbltextfloatsep
Distance between a multi-column float at the top or bottom of a page
and the main text.  Default @samp{20pt plus2pt minus4pt}.

@end ftable


@node \flushbottom
@section @code{\flushbottom}

@findex \flushbottom

The @code{\flushbottom} declaration makes all text pages the same
height, adding extra vertical space where necessary to fill out the
page.

This is the default if @code{twocolumn} mode is selected
(@pxref{Document class options}).


@node \raggedbottom
@section @code{\raggedbottom}
@findex \raggedbottom
@cindex stretch, omitting vertical

The @code{\raggedbottom} declaration makes all pages the natural
height of the material on that page.  No rubber lengths will be
stretched.


@node Page layout parameters
@section Page layout parameters

@cindex page layout parameters
@cindex parameters, page layout
@cindex layout, page parameters for
@cindex header, parameters for
@cindex footer, parameters for
@cindex running header and footer

@ftable @code
@item \headheight
Height of the box that contains the running head.  Default is
@samp{30pt}, except in the @code{book} class, where it varies with the
type size.

@item \headsep
Vertical distance between the bottom of the header line and the top of
the main text.  Default is @samp{25pt}, except in the @code{book}
class, where it varies with the type size.

@item \footskip
Distance from the baseline of the last line of text to the baseline of
the page footer.  Default is @samp{30pt}, except in the @code{book}
class, where it varies with the type size.

@item \linewidth
Width of the current line, decreased for each nested @code{list}
(@pxref{list}).  Specifically, it is smaller than @code{\textwidth} by
the sum of @code{\leftmargin} and @code{\rightmargin}
(@pxref{itemize}).  The default varies with the font size, paper
width, two-column mode, etc.  For an @code{article} document in
@samp{10pt}, it's set to @samp{345pt}; in two-column mode, that
becomes @samp{229.5pt}.

@item \textheight
The normal vertical height of the page body; the default varies with
the font size, document class, etc.  For an @code{article} or
@code{report} document in @samp{10pt}, it's set to
@samp{43\baselineskip}; for @code{book}, it's @samp{41\baselineskip}.
For @samp{11pt}, it's @samp{38\baselineskip} and for @samp{12pt},
@samp{36\baselineskip}.

@item \textwidth
The full horizontal width of the entire page body; the default varies
as usual.  For an @code{article} or @code{report} document, it's
@samp{345pt} at @samp{10pt}, @samp{360pt} at @samp{11pt}, and
@samp{390pt} at @samp{12pt}.  For a @code{book} document, it's
@samp{4.5in} at @samp{10pt}, and @samp{5in} at @samp{11pt} or
@samp{12pt}.

In multi-column output, @code{\textwidth} remains the width of the
entire page body, while @code{\columnwidth} is the width of one column
(@pxref{\twocolumn}).

In lists (@pxref{list}), @code{\textwidth} remains the width of the
entire page body (and @code{\columnwidth} the width of the entire
column), while @code{\linewidth} may decrease for nested lists.

Inside a minipage (@pxref{minipage}) or @code{\parbox}
(@pxref{\parbox}), all the width-related parameters are set to the
specified width, and revert to their normal values at the end of the
@code{minipage} or @code{\parbox}.

@findex \hsize
For completeness: @code{\hsize} is the @TeX{} primitive parameter used
when text is broken into lines.  It should not be used in normal
@LaTeX{} documents.

@item \topmargin
Space between the top of the @TeX{} page (one inch from the top of the
paper, by default) and the top of the header.  The default is computed
based on many other parameters: @code{\paperheight @minus{} 2in @minus{}
\headheight @minus{} \headsep @minus{} \textheight @minus{} \footskip}, and
then divided by two.

@item \topskip
Minimum distance between the top of the page body and the baseline of
the first line of text.  For the standard classes, the default is the
same as the font size, e.g., @samp{10pt} at @samp{10pt}.

@end ftable


@node Sectioning
@chapter Sectioning
@cindex sectioning

Sectioning commands provide the means to structure your text into units:

@ftable @code
@item \part
@item \chapter
(@code{report} and @code{book} class only)
@item \section
@item \subsection
@item \subsubsection
@item \paragraph
@item \subparagraph
@end ftable

All sectioning commands take the same general form, e.g.,

@example
\chapter[@var{toctitle}]@{@var{title}@}
@end example

In addition to providing the heading @var{title} in the main text, the
section title can appear in two other places:

@enumerate
@item
The table of contents.
@item
The running head at the top of the page.
@end enumerate

You may not want the same text in these places as in the main text.
To handle this, the sectioning commands have an optional argument
@var{toctitle} that, when given, specifies the text for these other
places.

@cindex *-form of sectioning commands
Also, all sectioning commands have @code{*}-forms that print
@var{title} as usual, but do not include a number and do not make an
entry in the table of contents.  For instance:

@example
\section*@{Preamble@}
@end example

@findex \appendix
@cindex appendix, creating
The @code{\appendix} command changes the way following sectional units
are numbered.  The @code{\appendix} command itself generates no text
and does not affect the numbering of parts.  The normal use of this
command is something like

@example
\chapter@{A Chapter@}
@dots{}
\appendix
\chapter@{The First Appendix@}
@end example

@findex secnumdepth @r{counter}
@cindex section numbers, printing
The @code{secnumdepth} counter controls printing of section numbers.
The setting

@example
\setcounter@{secnumdepth@}@{@var{level}@}
@end example

@noindent
suppresses heading numbers at any depth @math{> @var{level}}, where
@code{chapter} is level zero.  (@xref{\setcounter}.)


@node Cross references
@chapter Cross references
@cindex cross references

One reason for numbering things like figures and equations is to refer
the reader to them, as in ``See Figure 3 for more details.''

@menu
* \label::      Assign a symbolic name to a piece of text.
* \pageref::    Refer to a page number.
* \ref::        Refer to a section, figure or similar.
@end menu


@node \label
@section @code{\label}
@findex \label

Synopsis:

@example
\label@{@var{key}@}
@end example

A @code{\label} command appearing in ordinary text assigns to
@var{key} the number of the current sectional unit; one appearing
inside a numbered environment assigns that number to @var{key}.

A @var{key} name can consist of any sequence of letters, digits, or
punctuation characters.  Upper and lowercase letters are
distinguished, as usual.

To avoid accidentally creating two labels with the same name, it is
common to use labels consisting of a prefix and a suffix separated by
a colon or period. Some conventionally-used prefixes:

@table @code
@item ch
for chapters
@item sec
for lower-level sectioning commands
@item fig
for figures
@item tab
for tables
@item eq
for equations
@end table

Thus, a label for a figure would look like @code{fig:snark} or
@code{fig.snark}.


@node \pageref
@section @code{\pageref@{@var{key}@}}
@findex \pageref
@cindex cross referencing with page number
@cindex page number, cross referencing

Synopsis:

@example
\pageref@{@var{key}@}
@end example

The @code{\pageref}@{@var{key}@} command produces the page number of
the place in the text where the corresponding
@code{\label}@{@var{key}@} command appears.


@node \ref
@section @code{\ref@{@var{key}@}}
@findex \ref
@cindex cross referencing, symbolic
@cindex section number, cross referencing
@cindex equation number, cross referencing
@cindex figure number, cross referencing
@cindex footnote number, cross referencing

Synopsis:

@example
\ref@{@var{key}@}
@end example

The @code{\ref} command produces the number of the sectional unit,
equation, footnote, figure, @dots{}, of the corresponding
@code{\label} command (@pxref{\label}).  It does not produce any text,
such as the word `Section' or `Figure', just the bare number itself.


@node Environments
@chapter Environments
@cindex environments

@findex \begin
@findex \end

@LaTeX{} provides many environments for marking off certain text.
Each environment begins and ends in the same manner:

@example
\begin@{@var{envname}@}
...
\end@{@var{envname}@}
@end example

@menu
* abstract::    Produce an abstract.
* array::       Math arrays.
* center::      Centered lines.
* description:: Labelled lists.
* displaymath:: Formulas that appear on their own line.
* document::    Enclose the whole document.
* enumerate::   Numbered lists.
* eqnarray::    Sequences of aligned equations.
* equation::    Displayed equation.
* figure::      Floating figures.
* filecontents:: Writing multiple files from the source.
* flushleft::   Flushed left lines.
* flushright::  Flushed right lines.
* itemize::     Bulleted lists.
* letter::      Letters.
* list::        Generic list environment.
* math::        In-line math.
* minipage::    Miniature page.
* picture::     Picture with text, arrows, lines and circles.
* quotation::   Indented environment with paragraph indentation.
* quote::       Indented environment with no paragraph indentation.
* tabbing::     Align text arbitrarily.
* table::       Floating tables.
* tabular::     Align text in columns.
* thebibliography::     Bibliography or reference list.
* theorem::     Theorems, lemmas, etc.
* titlepage::   For hand crafted title pages.
* verbatim::    Simulating typed input.
* verse::       For poetry and other things.
@end menu


@node abstract
@section @code{abstract}

@findex abstract @r{environment}
@cindex abstracts

Synopsis:
@example
\begin@{abstract@}
...
\end@{abstract@}
@end example

Environment for producing an abstract, possibly of multiple paragraphs.


@node array
@section @code{array}
@findex array @r{environment}
@cindex arrays, math

Synopsis:

@example
\begin@{array@}@{@var{template}@}
@var{col1 text}&@var{col1 text}&@var{coln}@}\\
...
\end@{array@}
@end example

Math arrays are produced with the @code{array} environment, normally
within an @code{equation} environment (@pxref{equation}).  It has a
single mandatory @var{template} argument describing the number of
columns and the alignment within them.  Each column @var{col} is
specified by a single letter that tells how items in each row of that
column should be formatted, as follows:

@table @code
@item c
centered
@item l
flush left
@item r
flush right
@end table

@findex \\ @r{(for @code{array})}
Column entries are separated by @code{&}.  Column entries may include
other @LaTeX{} commands.  Each row of the array is terminated with
@code{\\}.

@findex @@@{...@}
In the template, the construct @code{@@@{@var{text}@}} puts @var{text}
between columns in each row.

Here's an example:

@example
\begin@{equation@}
  \begin@{array@}@{lrc@}
  left1 & right1 & centered1 \\
  left2 & right2 & centered2 \\
  \end@{array@}
\end@{equation@}
@end example

@findex \arraycolsep
The @code{\arraycolsep} parameter defines half the width of the space
separating columns; the default is @samp{5pt}.  @xref{tabular}, for other
parameters which affect formatting in @code{array} environments,
namely @code{\arrayrulewidth} and @code{\arraystretch}.

The @code{array} environment can only be used in math mode.


@node center
@section @code{center}

@findex center @r{environment}
@cindex centering text, environment for

Synopsis:

@example
\begin@{center@}
@var{line1} \\
@var{line2} \\
\end@{center@}
@end example

@findex \\ @r{(for @code{center})}
The @code{center} environment allows you to create a paragraph
consisting of lines that are centered within the left and right
margins on the current page.  Each line is terminated with the
string @code{\\}.

@menu
* \centering::          Declaration form of the @code{center} environment.
@end menu


@node \centering
@subsection @code{\centering}

@findex \centering
@cindex centering text, declaration for

The @code{\centering} declaration corresponds to the @code{center}
environment.  This declaration can be used inside an environment such
as @code{quote} or in a @code{parbox}.  Thus, the text of a figure or
table can be centered on the page by putting a @code{\centering}
command at the beginning of the figure or table environment.

Unlike the @code{center} environment, the @code{\centering} command
does not start a new paragraph; it simply changes how @LaTeX{} formats
paragraph units.  To affect a paragraph unit's format, the scope of
the declaration must contain the blank line or @code{\end} command (of
an environment such as quote) that ends the paragraph unit.

Here's an example:

@example
\begin@{quote@}
\centering
first line \\
second line \\
\end@{quote@}
@end example


@node description
@section @code{description}

@findex description @r{environment}
@cindex labelled lists, creating
@cindex description lists, creating

Synopsis:

@example
\begin@{description@}
\item [@var{label1}] @var{item1}
\item [@var{label2}] @var{item2}
...
\end@{description@}
@end example

@findex \item
The @code{description} environment is used to make labelled lists.  Each
@var{label} is typeset in bold, flush right.  The @var{item} text may
contain multiple paragraphs.

@cindex bold typewriter, avoiding
@cindex typewriter labels in lists
Another variation: since the bold style is applied to the labels, if
you typeset a label in typewriter using @code{\texttt}, you'll get
bold typewriter: @code{\item[\texttt@{bold and typewriter@}]}.  This
may be too bold, among other issues.  To get just typewriter, use
@code{\tt}, which resets all other style variations: @code{\item[@{\tt
plain typewriter@}]}.

For details about list spacing, see @ref{itemize}.


@node displaymath
@section @code{displaymath}

@findex displaymath @r{environment}

Synopsis:

@example
\begin@{displaymath@}
@var{math}
\end@{displaymath@}
@end example

@noindent or

@example
\[@var{math}\]
@end example

The @code{displaymath} environment (@code{\[...\]} is a synonym)
typesets the @var{math} text on its own line, centered by default.
The global @code{fleqn} option makes equations flush left; see
@ref{Document class options}.

No equation number is added to @code{displaymath} text; to get an
equation number, use the @code{equation} environment (@pxref{equation}).


@node document
@section @code{document}

@findex document @r{environment}

The @code{document} environment encloses the body of a document.
It is required in every @LaTeX{} document.  @xref{Starting and ending}.


@node enumerate
@section @code{enumerate}

@findex enumerate @r{environment}
@cindex lists of items, numbered

Synopsis:

@example
\begin@{enumerate@}
\item @var{item1}
\item @var{item2}
...
\end@{enumerate@}
@end example

The @code{enumerate} environment produces a numbered list.  Enumerations
can be nested within one another, up to four levels deep.  They can also
be nested within other paragraph-making environments, such as
@code{itemize} (@pxref{itemize}) and @code{description}
(@pxref{description}).

@findex \item
Each item of an enumerated list begins with an @code{\item} command.
There must be at least one @code{\item} command within the environment.

By default, the numbering at each level is done like this:

@enumerate
@item 1., 2., @dots{}
@item (a), (b), @dots{}
@item i., ii., @dots{}
@item A., B., @dots{}
@end enumerate

@findex \enumi
@findex \enumii
@findex \enumiii
@findex \enumiv
The @code{enumerate} environment uses the counters @code{\enumi}
through @code{\enumiv} counters (@pxref{Counters}).  If the optional
argument to @code{\item} is given, the counter is not incremented for
that item.

@findex \labelenumi
@findex \labelenumii
@findex \labelenumiii
@findex \labelenumiv
The @code{enumerate} environment uses the commands @code{\labelenumi}
through @code{\labelenumiv} to produce the default label.  So, you can
use @code{\renewcommand} to change the labels (@pxref{\newcommand &
\renewcommand}).  For instance, to have the first level use uppercase
letters:

@findex \Alph @r{example}
@example
\renewcommand@{\labelenumi@}@{\Alph@{enumi@}@}
@end example



@node eqnarray
@section @code{eqnarray}

@findex eqnarray @r{environment}
@cindex equations, aligning
@cindex aligning equations

@cindex align @r{environment, from @code{amsmath}}
@cindex amsmath @r{package, replacing @code{eqnarray}}
@cindex Madsen, Lars
First, a caveat: the @code{eqnarray} environment has some infelicities
which cannot be overcome; the article ``Avoid eqnarray!''@: by Lars
Madsen describes them in detail
(@url{http://tug.org/TUGboat/tb33-1/tb103madsen.pdf}).  The bottom
line is that it is better to use the @code{align} environment (and
others) from the @code{amsmath} package.

Nevertheless, here is a description of @code{eqnarray}:

@example
\begin@{eqnarray@}  @r{(or @code{eqnarray*})}
@var{formula1} \\
@var{formula2} \\
...
\end@{eqnarray@}
@end example

@findex \\ @r{(for @code{eqnarray})}
The @code{eqnarray} environment is used to display a sequence of
equations or inequalities.  It is similar to a three-column
@code{array} environment, with consecutive rows separated by @code{\\}
and consecutive items within a row separated by an @code{&}.

@findex \\* @r{(for @code{eqnarray})}
@code{\\*} can also be used to separate equations, with its normal
meaning of not allowing a page break at that line.

@findex \nonumber
@cindex equation numbers, omitting
An equation number is placed on every line unless that line has a
@code{\nonumber} command.  Alternatively, The @code{*}-form of the
environment (@code{\begin@{eqnarray*@} ... \end@{eqnarray*@}}) will
omit equation numbering entirely, while otherwise being the same as
@code{eqnarray}.

@findex \lefteqn
The command @code{\lefteqn} is used for splitting long formulas across
lines. It typesets its argument in display style flush left in a box of
zero width.


@node equation
@section @code{equation}

@findex equation @r{environment}
@cindex equations, environment for
@cindex formulas, environment for

Synopsis:

@example
\begin@{equation@}
@var{math}
\end@{equation@}
@end example

The @code{equation} environment starts a @code{displaymath}
environment (@pxref{displaymath}), e.g., centering the @var{math} text
on the page, and also places an equation number in the right margin.


@node figure
@section @code{figure}
@findex figure
@cindex inserting figures
@cindex figures, inserting

@example
\begin@{figure[*]@}[@var{placement}]
@var{figbody}
\label@{@var{label@}}
\caption[@var{loftitle}]@{@var{text}@}
\end@{figure@}
@end example

Figures are objects that are not part of the normal text, and are
instead ``floated'' to a convenient place, such as the top of a page.
Figures will not be split between two pages.

When typesetting in double-columns, the starred form produces a
full-width figure (across both columns).

@cindex placement of floats
@cindex specifier, float placement
The optional argument @code{[placement]} determines where @LaTeX{} will try
to place your figure.  There are four places where @LaTeX{} can possibly
put a float:

@table @code
@item t
(Top)---at the top of a text page.

@item b
(Bottom)---at the bottom of a text page.  However, @code{b} is not
allowed for full-width floats (@code{figure*}) with double-column
output.  To ameliorate this, use the @code{stfloats} or
@code{dblfloatfix} package, but see the discussion at caveats in the
FAQ: @url{http://www.tex.ac.uk/cgi-bin/texfaq2html?label=2colfloat}.

@item h
(Here)---at the position in the text where the @code{figure} environment
appears.  However, @code{t} is not allowed by itself; @code{t} is
automatically added.

@cindex here, putting floats
@cindex @code{float} package
To absolutely force a figure to appear ``here'', you can
@code{\usepackage@{float@}} and use the @code{H} specifier which it
defines.  For further discussion, see the FAQ entry at
@url{http://www.tex.ac.uk/cgi-bin/texfaq2html?label=figurehere}.

@item p
(Page of floats)---on a separate float page, which is a page
containing no text, only floats.

@item !
Used in addition to one of the above; for this float only, @LaTeX{}
ignores the restrictions on both the number of floats that can appear
and the relative amounts of float and non-float text on the page.
The @code{!} specifier does @emph{not} mean ``put the float here'';
see above.

@end table

The standard @code{report} and @code{article} classes use the default placement
@code{tbp}.

The body of the figure is made up of whatever text, @LaTeX{} commands,
etc.@: you wish.

@findex \caption
The @code{\caption} command specifies caption @var{text} for the
figure.  The caption is numbered by default.  If @var{loftitle} is
present, it is used in the list of figures instead of @var{text}
(@pxref{Tables of contents}).

Parameters relating to fractions of pages occupied by float and
non-float text:

@ftable @code
@findex \bottomfraction
The maximum fraction of the page allowed to be occupied by floats at
the bottom; default @samp{.3}.

@item \floatpagefraction
The minimum fraction of a float page that must be occupied by floats;
default @samp{.5}.

@item \textfraction
Minimum fraction of a page that must be text; if floats take up too
much space to preserve this much text, floats will be moved to a
different page.  The default is @samp{.2}.

@item \topfraction
Maximum fraction at the top of a page that may be occupied before
floats; default @samp{.7}.
@end ftable

Parameters relating to vertical space around floats:

@ftable @code
@item \floatsep
Space between floats at the top or bottom of a page; default
@samp{12pt plus2pt minus2pt}.

@item \intextsep
Space above and below a float in the middle of the main text; default
@samp{12pt plus2pt minus2pt} for @samp{10pt} and @samp{11pt} styles,
@samp{14pt plus4pt minus4pt} for @samp{12pt}.

@item \textfloatsep
Space between the last (first) float at the top (bottom) of a page;
default @samp{20pt plus2pt minus4pt}.
@end ftable

Counters relating to the number of floats on a page:

@ftable @code
@item bottomnumber
Maximum number of floats that can appear at the bottom of a text page;
default 1.

@item dbltopnumber
Maximum number of full-sized floats that can appear at the top of a
two-column page; default 2.

@item topnumber
Maximum number of floats that can appear at the top of a text page;
default 2.

@item totalnumber
Maximum number of floats that can appear on a text page; default 3.
@end ftable

The principal @TeX{} FAQ entry relating to floats:
@url{http://www.tex.ac.uk/cgi-bin/texfaq2html?label=floats}.


@node filecontents
@section @code{filecontents}: Create external files
@findex filecontents
@cindex external files, creating
@cindex writing external files

Synopsis:

@example
\begin@{filecontents@}@{@var{filename}@}
@var{contents-of-file}
\end@{filecontents@}
...
\documentclass@{@var{my-document-class}@}
@end example

@cindex initial command
@findex \documentclass, commands before
The @code{filecontents} environment is an @dfn{initial command},
meaning that it can be used only before the @code{\documentclass}
command, as in the synopsis above.

@LaTeX{} will create a file named @var{filename} with the content
@var{contents-of-file} preceded by a header comment indicating how and
when the file was generated. If the file already exists then nothing will
happen.

You can also use the @code{filecontents} package, which has the
following advantages:

@itemize
@item
If the file already exists, then it will be overwritten.

@item
You can use the @code{filecontents} environment at any point after the
declaration @code{\usepackage@{filecontents@}}, not just before
@code{\documentclass}.

@item
The @code{filecontents} package also provides a @code{filecontents*}
environment which is used in the same way as the @code{filecontents}
environment except that it won't insert any leading comment, so it is
better suited to create files which aren't in @LaTeX{} format.

@end itemize

The @code{filecontents} environment only creates the file, and is
unrelated to using the created file.  So you need to use, for
instance, @code{\input} or @code{\usepackage} or @code{\bibliography}
or whatever is applicable, to use the created file.

This environment is also useful to make a document in a self-contained
file, for example, for a bug report, or to keep the content of a
@file{.bib} file in the same file as the main document.


@node flushleft
@section @code{flushleft}
@findex flushleft @r{environment}
@cindex left-justifying text, environment for
@cindex ragged right text, environment for

@example
\begin@{flushleft@}
@var{line1} \\
@var{line2} \\
...
\end@{flushleft@}
@end example

@findex \\ @r{for @code{flushleft}}
The @code{flushleft} environment allows you to create a paragraph
consisting of lines that are flush to the left-hand margin and ragged
right Each line must be terminated with the string @code{\\}.

@menu
* \raggedright::        Declaration form of the @code{flushleft} environment.
@end menu


@node \raggedright
@subsection @code{\raggedright}
@findex \raggedright
@cindex ragged right text
@cindex left-justifying text
@cindex justification, ragged right

The @code{\raggedright} declaration corresponds to the
@code{flushleft} environment.  This declaration can be used inside an
environment such as @code{quote} or in a @code{parbox}.

Unlike the @code{flushleft} environment, the @code{\raggedright}
command does not start a new paragraph; it only changes how @LaTeX{}
formats paragraph units.  To affect a paragraph unit's format, the
scope of the declaration must contain the blank line or @code{\end}
command that ends the paragraph unit.


@node flushright
@section @code{flushright}
@findex flushright @r{environment}
@cindex ragged left text, environment for
@cindex right-justifying text, environment for

@example
\begin@{flushright@}
@var{line1} \\
@var{line2} \\
...
\end@{flushright@}
@end example

@findex \\ (for @code{flushright})
The @code{flushright} environment allows you to create a paragraph
consisting of lines that are flush to the right-hand margin and ragged
left.  Each line must be terminated with the string @code{\\}.

@menu
* \raggedleft::   Declaration form of the @code{flushright} environment.
@end menu


@node \raggedleft
@subsection @code{\raggedleft}
@findex \raggedleft
@cindex ragged left text
@cindex justification, ragged left
@cindex right-justifying text

The @code{\raggedleft} declaration corresponds to the
@code{flushright} environment.  This declaration can be used inside an
environment such as @code{quote} or in a @code{parbox}.

Unlike the @code{flushright} environment, the @code{\raggedleft}
command does not start a new paragraph; it only changes how @LaTeX{}
formats paragraph units.  To affect a paragraph unit's format, the
scope of the declaration must contain the blank line or @code{\end}
command that ends the paragraph unit.


@node itemize
@section @code{itemize}
@findex itemize @r{environment}
@findex \item
@cindex lists of items
@cindex unordered lists
@cindex bulleted lists

Synopsis:

@example
\begin@{itemize@}
\item @var{item1}
\item @var{item2}
...
\end@{itemize@}
@end example

The @code{itemize} environment produces an ``unordered'', ``bulleted''
list.  Itemizations can be nested within one another, up to four
levels deep.  They can also be nested within other paragraph-making
environments, such as @code{enumerate} (@pxref{enumerate}).

Each item of an @code{itemize} list begins with an @code{\item} command.
There must be at least one @code{\item} command within the environment.

By default, the marks at each level look like this:

@enumerate
@item @bullet{} (bullet)
@item @b{-@w{-}} (bold en-dash)
@item * (asterisk)
@iftex
@item @math{\cdot} (centered dot)
@end iftex
@ifnottex
@item . (centered dot, rendered here as a period)
@end ifnottex
@end enumerate

@findex \labelitemi
@findex \labelitemii
@findex \labelitemiii
@findex \labelitemiv
The @code{itemize} environment uses the commands @code{\labelitemi}
through @code{\labelitemiv} to produce the default label.  So, you can
use @code{\renewcommand} to change the labels.  For instance, to have
the first level use diamonds:

@example
\renewcommand@{\labelitemi@}@{$\diamond$@}
@end example

@findex \leftmargin
@findex \leftmargini
@findex \leftmarginii
@findex \leftmarginiii
@findex \leftmarginiv
@findex \leftmarginv
@findex \leftmarginvi
The @code{\leftmargini} through @code{\leftmarginvi} parameters define
the distance between the left margin of the enclosing environment and
the left margin of the list.  By convention, @code{\leftmargin} is set
to the appropriate @code{\leftmargin@var{N}} when a new level of
nesting is entered.

The defaults vary from @samp{.5em} (highest levels of nesting) to
@samp{2.5em} (first level), and are a bit reduced in two-column mode.
This example greatly reduces the margin space for outermost lists:

@example
\setlength@{\leftmargini@}@{1.25em@} % default 2.5em
@end example

@c xx should be in its own generic section
Some parameters that affect list formatting:

@ftable @code
@item \itemindent
Extra indentation before each item in a list; default zero.

@item \labelsep
Space between the label and text of an item; default @samp{.5em}.

@item \labelwidth
Width of the label; default @samp{2em}, or @samp{1.5em} in two-column mode.

@item \listparindent
Extra indentation added to second and subsequent paragraphs within a
list item; default @samp{0pt}.

@item \rightmargin
Horizontal distance between the right margin of the list and the
enclosing environment; default @samp{0pt}, except in the @code{quote},
@code{quotation}, and @code{verse} environments, where it is set equal
to @code{\leftmargin}.

@end ftable

Parameters affecting vertical spacing between list items (rather
loose, by default).

@ftable @code
@item \itemsep
Vertical space between items.  The default is @code{2pt plus1pt
minus1pt} for @code{10pt} documents, @code{3pt plus2pt minus1pt} for
@code{11pt}, and @code{4.5pt plus2pt minus1pt} for @code{12pt}.

@item \parsep
Extra vertical space between paragraphs within a list item.  Defaults
are the same as @code{\itemsep}.

@item \topsep
Vertical space between the first item and the preceding paragraph.
For top-level lists, the default is @code{8pt plus2pt minus4pt} for
@code{10pt} documents, @code{9pt plus3pt minus5pt} for @code{11pt},
and @code{10pt plus4pt minus6pt} for @code{12pt}.  These are reduced
for nested lists.

@item \partopsep
Extra space added to @code{\topsep} when the list environment starts a
paragraph.  The default is @code{2pt plus1pt minus1pt} for @code{10pt}
documents, @code{3pt plus1pt minus1pt} for @code{11pt}, and @code{3pt
plus2pt minus2pt} for @code{12pt}.

@end ftable

@findex \parskip @r{example}
Especially for lists with short items, it may be desirable to elide
space between items.  Here is an example defining an @code{itemize*}
environment with no extra spacing between items, or between paragraphs
within a single item (@code{\parskip} is not list-specific,
@pxref{\parskip}):

@example
\newenvironment@{itemize*@}%
  @{\begin@{itemize@}%
    \setlength@{\itemsep@}@{0pt@}%
    \setlength@{\parsep@}@{0pt@}@}%
    \setlength@{\parskip@}@{0pt@}@}%
  @{\end@{itemize@}@}
@end example


@node letter
@section @code{letter} environment: writing letters
@findex letter

This environment is used for creating letters.  @xref{Letters}.


@node list
@section @code{list}
@findex list
@cindex lists of items, generic

The @code{list} environment is a generic environment which is used for
defining many of the more specific environments. It is seldom used in
documents, but often in macros.

@example
\begin@{list@}@{@var{labeling}@}@{@var{spacing}@}
\item @var{item1}
\item @var{item2}
...
\end@{list@}
@end example

The mandatory @var{labeling} argument specifies how items should be
labelled (unless the optional argument is supplied to @code{\item}).
This argument is a piece of text that is inserted in a box to form the
label.  It can and usually does contain other @LaTeX{} commands.

The mandatory @var{spacing} argument contains commands to change the
spacing parameters for the list.  This argument will most often be
empty, i.e., @code{@{@}}, which leaves the default spacing.

The width used for typesetting the list items is specified by
@code{\linewidth} (@pxref{Page layout parameters}).


@node math
@section @code{math}

@findex math @r{environment}
@cindex in-line formulas

Synopsis:

@example
\begin@{math@}
@var{math}
\end@{math@}
@end example

The @code{math} environment inserts the given @var{math} within the
running text.  @code{\(...\))} and @code{$...$} are synonyms.
@xref{Math formulas}.


@node minipage
@section @code{minipage}

@findex minipage @r{environment}
@cindex minipage, creating a

@example
\begin@{minipage@}[@var{position}][@var{height}][@var{inner-pos}]@{@var{width}@}
@var{text}
\end@{minipage@}
@end example

The @code{minipage} environment typesets its body @var{text} in a
block that will not be broken across pages.  This is similar to the
@code{\parbox} command (@pxref{\parbox}), but unlike @code{\parbox},
other paragraph-making environments can be used inside a minipage.

@c (xxref positions)
The arguments are the same as for @code{\parbox} (@pxref{\parbox}).

@cindex indentation of paragraphs, in minipage
@cindex paragraph indentation, in minipage
@findex \parindent
By default, paragraphs are not indented in the @code{minipage}
environment.  You can restore indentation with a command such as
@code{\setlength@{\parindent@}@{1pc@}} command.

@cindex footnotes in figures
@cindex figures, footnotes in
Footnotes in a @code{minipage} environment are handled in a way that is
particularly useful for putting footnotes in figures or tables.  A
@code{\footnote} or @code{\footnotetext} command puts the footnote at
the bottom of the minipage instead of at the bottom of the page, and it
uses the @code{\mpfootnote} counter instead of the ordinary
@code{footnote} counter (@pxref{Counters}).

However, don't put one minipage inside another if you are using
footnotes; they may wind up at the bottom of the wrong minipage.


@node picture
@section @code{picture}

@findex picture
@cindex creating pictures
@cindex pictures, creating

@example
\begin@{picture@}(width,height)(x offset,y offset)
@dots{} @var{picture commands} @dots{}
\end@{picture@}
@end example

@findex \unitlength
The @code{picture} environment allows you to create just about any
kind of picture you want containing text, lines, arrows and circles.
You tell @LaTeX{} where to put things in the picture by specifying
their coordinates.  A coordinate is a number that may have a decimal
point and a minus sign---a number like @code{5}, @code{0.3} or
@code{-3.1416}.  A coordinate specifies a length in multiples of the
unit length @code{\unitlength}, so if @code{\unitlength} has been set
to @code{1cm}, then the coordinate 2.54 specifies a length of 2.54
centimeters.

You should only change the value of @code{\unitlength}, using the
@code{\setlength} command, outside of a @code{picture} environment.
The default value is @code{1pt}.

A position is a pair of coordinates, such as @code{(2.4,-5)}, specifying
the point with x-coordinate @code{2.4} and y-coordinate @code{-5}.
Coordinates are specified in the usual way with respect to an origin,
which is normally at the lower-left corner of the picture.  Note that
when a position appears as an argument, it is not enclosed in braces;
the parentheses serve to delimit the argument.

The @code{picture} environment has one mandatory argument, which is a
@code{position}.  It specifies the size of the picture.  The environment
produces a rectangular box with width and height determined by this
argument's x- and y-coordinates.

The @code{picture} environment also has an optional @code{position}
argument, following the @code{size} argument, that can change the
origin.  (Unlike ordinary optional arguments, this argument is not
contained in square brackets.) The optional argument gives the
coordinates of the point at the lower-left corner of the picture
(thereby determining the origin).  For example, if @code{\unitlength}
has been set to @code{1mm}, the command

@example
\begin@{picture@}(100,200)(10,20)
@end example

@noindent produces a picture of width 100 millimeters and height 200
millimeters, whose lower-left corner is the point (10,20) and whose
upper-right corner is therefore the point (110,220).  When you first
draw a picture, you typically omit the optional argument, leaving the
origin at the lower-left corner.  If you then want to modify your
picture by shifting everything, you can just add the appropriate
optional argument.

The environment's mandatory argument determines the nominal size of the
picture.  This need bear no relation to how large the picture really is;
@LaTeX{} will happily allow you to put things outside the picture, or even
off the page.  The picture's nominal size is used by @LaTeX{} in determining
how much room to leave for it.

Everything that appears in a picture is drawn by the @code{\put}
command. The command

@example
\put (11.3,-.3)@{...@}
@end example

@noindent puts the object specified by @code{...} in the
picture, with its reference point at coordinates @math{(11.3,-.3)}.
The reference points for various objects will be described below.

@findex lR box
The @code{\put} command creates an @dfn{LR box}.  You can put anything
that can go in an @code{\mbox} (@pxref{\mbox}) in the text argument of
the @code{\put} command.  When you do this, the reference point will
be the lower left corner of the box.

The @code{picture} commands are described in the following sections.

@menu
* \circle::             Draw a circle.
* \makebox (picture)::  Draw a box of the specified size.
* \framebox (picture):: Draw a box with a frame around it.
* \dashbox::            Draw a dashed box.
* \frame::              Draw a frame around an object.
* \line::               Draw a straight line.
* \linethickness::      Set the line thickness.
* \thicklines::         A heavier line thickness.
* \thinlines::          The default line thickness.
* \multiput::           Draw multiple instances of an object.
* \oval::               Draw an ellipse.
* \put::                Place an object at a specified place.
* \shortstack::         Make a pile of objects.
* \vector::             Draw a line with an arrow.
@end menu


@node \circle
@subsection @code{\circle}
@findex \circle

Synopsis:
@example
\circle[*]@{@var{diameter}@}
@end example

The @code{\circle} command produces a circle with a diameter as close
to the specified one as possible.  The @code{*}-form of the command
draws a solid circle.

Circles up to 40@dmn{pt} can be drawn.


@node \makebox (picture)
@subsection @code{\makebox}
@findex \makebox @r{(for @code{picture})}

Synopsis:
@example
\makebox(@var{width},@var{height})[@var{position}]@{@var{text}@}
@end example

The @code{\makebox} command for the picture environment is similar to
the normal @code{\makebox} command except that you must specify a
@var{width} and @var{height} in multiples of @code{\unitlength}.

The optional argument, @code{[@var{position}]}, specifies the quadrant that
your @var{text} appears in.  You may select up to two of the following:

@table @code
@item t
Moves the item to the top of the rectangle.

@item b
Moves the item to the bottom.

@item l
Moves the item to the left.

@item r
Moves the item to the right.

@end table

@xref{\makebox}.


@node \framebox (picture)
@subsection @code{\framebox}
@findex \framebox

Synopsis:

@example
\framebox(@var{width},@var{height})[@var{pos}]@{...@}
@end example

The @code{\framebox} command is like @code{\makebox} (see previous
section), except that it puts a frame around the outside of the box
that it creates.

@findex \fboxrule
@findex \fboxsep
The @code{\framebox} command produces a rule of thickness
@code{\fboxrule}, and leaves a space @code{\fboxsep} between the rule
and the contents of the box.


@node \dashbox
@subsection @code{\dashbox}

@findex \dashbox

Draws a box with a dashed line.  Synopsis:

@example
\dashbox@{@var{dlen}@}(@var{rwidth},@var{rheight})[@var{pos}]@{@var{text}@}
@end example

@code{\dashbox} creates a dashed rectangle around @var{text} in a
@code{picture} environment.  Dashes are @var{dlen} units long, and the
rectangle has overall width @var{rwidth} and height @var{rheight}.
The @var{text} is positioned at optional @var{pos}.  @c xxref positions.

A dashed box looks best when the @var{rwidth} and @var{rheight} are
multiples of the @var{dlen}.


@node \frame
@subsection @code{\frame}
@findex \frame

Synopsis:

@example
\frame@{@var{text}@}
@end example

The @code{\frame} command puts a rectangular frame around @var{text}.
The reference point is the bottom left corner of the frame.  No extra
space is put between the frame and the object.


@node \line
@subsection @code{\line}
@findex \line

Synopsis:

@example
\line(@var{xslope},@var{yslope})@{@var{length}@}
@end example

The @code{\line} command draws a line with the given @var{length} and
slope @var{xslope}/@var{yslope}.

@cindex @code{pict2e} package
@cindex graphics packages
Standard @LaTeX{} can only draw lines with @math{@var{slope} = x/y},
where @math{x} and @math{y} have integer values from @minus{}6
through@tie{}6.  For lines of any slope, and plenty of other shapes,
see @code{pict2e} and many other packages on CTAN.


@node \linethickness
@subsection @code{\linethickness}
@findex \linethickness

The @code{\linethickness@{@var{dim}@}} command declares the thickness
of horizontal and vertical lines in a picture environment to be
@var{dim}, which must be a positive length.

@code{\linethickness} does not affect the thickness of slanted lines,
circles, or the quarter circles drawn by @code{\oval}.


@node \thicklines
@subsection @code{\thicklines}
@findex \thicklines

The @code{\thicklines} command is an alternate line thickness for
horizontal and vertical lines in a picture environment;
cf.@tie{}@ref{\linethickness} and @ref{\thinlines}.


@node \thinlines
@subsection @code{\thinlines}
@findex \thinlines

The @code{\thinlines} command is the default line thickness for
horizontal and vertical lines in a picture environment;
cf.@tie{}@ref{\linethickness} and @ref{\thicklines}.


@node \multiput
@subsection @code{\multiput}
@findex \multiput

Synopsis:
@example
\multiput(@var{x},@var{y})(@var{delta_x},@var{delta_y})@{@var{n}@}@{@var{obj}@}
@end example

The @code{\multiput} command copies the object @var{obj} in a regular
pattern across a picture.  @var{obj} is first placed at position
@math{(x,y)}, then at @math{(x+\delta x,y+\delta y)}, and so on,
@var{n} times.


@node \oval
@subsection @code{\oval}
@findex \oval

Synopsis:

@example
\oval(@var{width},@var{height})[@var{portion}]
@end example

The @code{\oval} command produces a rectangle with rounded corners.
The optional argument @var{portion} allows you to select part of the
oval via the following:

@table @code
@item t
selects the top portion;
@item b
selects the bottom portion;
@item r
selects the right portion;
@item l
selects the left portion.
@end table

The ``corners'' of the oval are made with quarter circles with a
maximum radius of 20@dmn{pt}, so large ``ovals'' will look more like
boxes with rounded corners.


@node \put
@subsection @code{\put}
@findex \put

Synopsis:

@example
\put(@var{xcoord},@var{ycoord})@{ ... @}
@end example

The @code{\put} command places the material specified by the
(mandatory) argument in braces at the given coordinate,
(@var{xcoord},@var{ycoord}).


@node \shortstack
@subsection @code{\shortstack}
@findex \shortstack

Synopsis:

@example
\shortstack[@var{position}]@{...\\...\\...@}
@end example

The @code{\shortstack} command produces a stack of objects.  The valid
positions are:

@table @code
@item r
Move the objects to the right of the stack.
@item l
Move the objects to the left of the stack
@item c
Move the objects to the centre of the stack (default)
@end table

@findex \\ @r{(for @code{\shortstack} objects)}
Objects are separated with @code{\\}.


@node \vector
@subsection @code{\vector}
@findex \vector

Synopsis:

@example
\vector(@var{xslope},@var{yslope})@{@var{length}@}
@end example

The @code{\vector} command draws a line with an arrow of the specified
length and slope.  The @math{@var{xslope}} and @math{@var{yslope}}
values must lie between @minus{}4 and +4, inclusive.


@node quotation
@section @code{quotation}

@findex quotation
@cindex quoted text with paragraph indentation, displaying
@cindex displaying quoted text with paragraph indentation
@cindex paragraph indentations in quoted text

Synopsis:

@example
\begin@{quotation@}
@var{text}
\end@{quotation@}
@end example

The margins of the @code{quotation} environment are indented on both
the left and the right.  The text is justified at both margins.
Leaving a blank line between text produces a new paragraph.

Unlike the @code{quote} environment, each paragraph is indented
normally.


@node quote
@section @code{quote}

@findex quote
@cindex quoted text without paragraph indentation, displaying
@cindex displaying quoted text without paragraph indentation
@cindex paragraph indentations in quoted text, omitting

Synopsis:

@example
\begin@{quote@}
@var{text}
\end@{quote@}
@end example

The margins of the @code{quote} environment are indented on both the
left and the right.  The text is justified at both margins.  Leaving a
blank line between text produces a new paragraph.

Unlike the @code{quotation} environment, paragraphs are not indented.


@node tabbing
@section @code{tabbing}

@findex tabbing @r{environment}
@cindex tab stops, using
@cindex lining text up using tab stops
@cindex alignment via tabbing

Synopsis:

@example
\begin@{tabbing@}
@var{row1col1} \= @var{row1col2} \= @var{row1col3} \= @var{row1col4} \\
@var{row2col1} \>                \> @var{row2col3} \\
...
\end@{tabbing@}
@end example

The @code{tabbing} environment provides a way to align text in
columns.  It works by setting tab stops and tabbing to them much as
was done on an ordinary typewriter.  It is best suited for cases where
the width of each column is constant and known in advance.

This environment can be broken across pages, unlike the @code{tabular}
environment.

The following commands can be used inside a @code{tabbing} environment:

@ftable @code
@item \\ @r{(tabbing)}
End a line.

@item \= @r{(tabbing)}
Sets a tab stop at the current position.

@item \> @r{(tabbing)}
@findex \>
Advances to the next tab stop.

@item \<
Put following text to the left of the local margin (without changing
the margin).  Can only be used at the start of the line.

@item \+
Moves the left margin of the next and all the
following commands one tab stop to the right, beginning tabbed line if
necessary.

@item \-
Moves the left margin of the next and all the
following commands one tab stop to the left, beginning tabbed line if
necessary.

@item \' @r{(tabbing)}
Moves everything that you have typed so far in the
current column, i.e. everything from the most recent @code{\>},
@code{\<}, @code{\'}, @code{\\}, or @code{\kill} command, to the right
of the previous column, flush against the current column's tab stop.

@item \` @r{(tabbing)}
Allows you to put text flush right against any tab stop, including tab
stop@tie{}0.  However, it can't move text to the right of the last column
because there's no tab stop there.  The @code{\`} command moves all the
text that follows it, up to the @code{\\} or @code{\end@{tabbing@}}
command that ends the line, to the right margin of the tabbing
environment.  There must be no @code{\>} or @code{\'} command between
the @code{\`} and the command that ends the line.

@item \a @r{(tabbing)}
@findex \a' @r{(acute accent in tabbing)}
@findex \a` @r{(grave accent in tabbing)}
@findex \a= @r{(macron accent in tabbing)}
In a @code{tabbing} environment, the commands @code{\=}, @code{\'} and
@code{\`} do not produce accents as usual (@pxref{Accents}).  Instead,
the commands @code{\a=}, @code{\a'} and @code{\a`} are used.

@item \kill
Sets tab stops without producing text.  Works just like @code{\\}
except that it throws away the current line instead of producing
output for it.  The effect of any @code{\=}, @code{\+} or @code{\-}
commands in that line remain in effect.

@item \poptabs
@findex \poptabs
Restores the tab stop positions saved by the last @code{\pushtabs}.

@item \pushtabs
Saves all current tab stop positions. Useful for temporarily changing
tab stop positions in the middle of a @code{tabbing} environment.

@item \tabbingsep
Distance to left of tab stop moved by @code{\'}.

@end ftable

This example typesets a Pascal function in a traditional format:

@example
\begin@{tabbing@}
function \= fact(n : integer) : integer;\\
         \> begin \= \+ \\
               \> if \= n $>$ 1 then \+ \\
                        fact := n * fact(n-1) \- \\
                  else \+ \\
                        fact := 1; \-\- \\
            end;\\
\end@{tabbing@}
@end example


@node table
@section @code{table}

@findex table
@cindex tables, creating
@cindex creating tables

Synopsis:

@example
 \begin@{table@}[placement]

  body of the table

 \caption@{table title@}
 \end@{table@}
@end example

Tables are objects that are not part of the normal text, and are
usually ``floated'' to a convenient place, like the top of a page.
Tables will not be split between two pages.

The optional argument @code{[placement]} determines where @LaTeX{} will try
to place your table.  There are four places where @LaTeX{} can possibly put
a float; these are the same as that used with the @code{figure}
environment, and described there (@pxref{figure}).

The standard @code{report} and @code{article} classes use the default
placement @code{[tbp]}.

The body of the table is made up of whatever text, @LaTeX{} commands, etc.,
you wish.  The @code{\caption} command allows you to title your table.


@node tabular
@section @code{tabular}
@findex tabular @r{environment}
@cindex lines in tables
@cindex lining text up in tables

Synopsis:

@example
\begin@{tabular@}[pos]@{cols@}
column 1 entry & column 2 entry ... & column n entry \\
...
\end@{tabular@}
@end example

@noindent
or

@example
\begin@{tabular*@}@{width@}[pos]@{cols@}
column 1 entry & column 2 entry ... & column n entry \\
...
\end@{tabular*@}
@end example

These environments produce a box consisting of a sequence of rows of
items, aligned vertically in columns.

@findex \\ @r{for @code{tabular}}
@code{\\} must be used to specify the end of each row of the table,
except for the last, where it is optional---unless an @code{\hline}
command (to put a rule below the table) follows.

The mandatory and optional arguments consist of:

@table @code
@item width
Specifies the width of the @code{tabular*} environment.  There must be
rubber space between columns that can stretch to fill out the specified
width.

@item pos
Specifies the vertical position; default is alignment on the centre of
the environment.

@table @code
@item t
align on top row

@item b
align on bottom row
@end table

@item cols
Specifies the column formatting.  It consists of a sequence of the
following specifiers, corresponding to the sequence of columns and
intercolumn material.

@table @code
@item l
A column of left-aligned items.

@item r
A column of right-aligned items.

@item c
A column of centered items.

@item |
A vertical line the full height and depth of the environment.

@item @@@{@var{text}@}
This inserts @var{text} in every row.  An @@-expression suppresses the
intercolumn space normally inserted between columns; any desired space
before the adjacent item must be included in @var{text}.

To insert commands that are automatically executed before a given
column, you have to load the @code{array} package and use the
@code{>@{...@}} specifier.
@c xx should fully explain array, tabularx, and all other base packages...

@findex \extracolsep
An @code{\extracolsep@{wd@}} command in an @@-expression causes an
extra space of width @code{wd} to appear to the left of all subsequent
columns, until countermanded by another @code{\extracolsep} command.
Unlike ordinary intercolumn space, this extra space is not suppressed
by an @@-expression.  An @code{\extracolsep} command can be used only
in an @@-expression in the @code{cols} argument.

@item p@{@var{wd}@}
Produces a column with each item typeset in a parbox of width
@var{wd}, as if it were the argument of a
@code{\parbox[t]@{@var{wd}@}} command.  However, a @code{\\} may not
appear in the item, except in the following situations:

@enumerate
@item
inside an environment like @code{minipage}, @code{array}, or @code{tabular}.
@item
inside an explicit @code{\parbox}.
@item
in the scope of a @code{\centering}, @code{\raggedright}, or @code{\raggedleft}
declaration.  The latter declarations must appear inside braces or an
environment when used in a @code{p}-column element.
@end enumerate

@item *@{@var{num}@}@{@var{cols}@}
Equivalent to @var{num} copies of @var{cols}, where @var{num} is a
positive integer and @var{cols} is any list of column-specifiers,
which may contain another @code{*-expression}.

@end table
@end table

Parameters that control formatting:
@c xx defaults, own node (xref from array)?

@ftable @code
@item \arrayrulewidth
Thickness of the rule created by @code{|}, @code{\hline}, and
@code{\vline} in the @code{tabular} and @code{array} environments; the
default is @samp{.4pt}.

@item \arraystretch
Scaling of spacing between rows in the @code{tabular} and @code{array}
environments; default is @samp{1}, for no scaling.

@item \doublerulesep
Horizontal distance between the vertical rules produced by @code{||}
in the @code{tabular} and @code{array} environments; default is @samp{2pt}.

@item \tabcolsep
Half the width of the space between columns; default is @samp{6pt}.

@end ftable

The following commands can be used inside a @code{tabular}
environment:

@menu
* \multicolumn::        Make an item spanning several columns.
* \cline::              Draw a horizontal line spanning some columns.
* \hline::              Draw a horizontal line spanning all columns.
* \vline::              Draw a vertical line.
@end menu


@node \multicolumn
@subsection @code{\multicolumn}
@findex \multicolumn

Synopsis:
@example
\multicolumn@{@var{cols}@}@{@var{pos}@}@{@var{text}@}
@end example

The @code{\multicolumn} command makes an entry that spans several
columns.  The first mandatory argument, @var{cols}, specifies the
number of columns to span.  The second mandatory argument, @var{pos},
specifies the formatting of the entry; @code{c} for centered, @code{l}
for flushleft, @code{r} for flushright.  The third mandatory argument,
@var{text}, specifies what text to put in the entry.

Here's an example showing two columns separated by an en-dash;
@code{\multicolumn} is used for the heading:

@example
\begin@{tabular@}@{r@@@{--@}l@}
\multicolumn@{2@}@{c@}@{\bf Unicode@}\cr
   0x80&0x7FF   \cr
  0x800&0xFFFF  \cr
0x10000&0x1FFFF \cr
\end@{tabular@}
@end example


@node \cline
@subsection @code{\cline}
@findex \cline

Synopsis:

@example
\cline@{@var{i}-@var{j}@}
@end example

The @code{\cline} command draws horizontal lines across the columns
specified, beginning in column @var{i} and ending in column @var{j},
which are specified in the mandatory argument.


@node \hline
@subsection @code{\hline}
@findex \hline

The @code{\hline} command draws a horizontal line the width of the
enclosing @code{tabular} or @code{array} environment.  It's most
commonly used to draw a line at the top, bottom, and between the rows
of a table.


@node \vline
@subsection @code{\vline}
@findex \vline

The @code{\vline} command will draw a vertical line extending the full
height and depth of its row.  An @code{\hfill} command can be used to
move the line to the edge of the column.  It can also be used in an
@@-expression.


@node thebibliography
@section @code{thebibliography}

@findex thebibliography
@cindex bibliography, creating (manually)

Synopsis:

@example
\begin@{thebibliography@}@{@var{widest-label}@}
\bibitem[@var{label}]@{@var{cite_key@}}
...
\end@{thebibliography@}
@end example

The @code{thebibliography} environment produces a bibliography or
reference list.

In the @code{article} class, this reference list is labelled
``References''; in the @code{report} class, it is labelled
``Bibliography''.  You can change the label (in the standard classes)
by redefining the command @code{\refname}.  For instance, this
eliminates it entirely:

@example
\renewcommand@{\refname@}@{@}
@end example

The mandatory @var{widest-label} argument is text that, when typeset,
is as wide as the widest item label produced by the @code{\bibitem}
commands.  It is typically given as @code{9} for bibliographies with
less than 10 references, @code{99} for ones with less than 100, etc.

@menu
* \bibitem::            Specify a bibliography item.
* \cite::               Refer to a bibliography item.
* \nocite::             Include an item in the bibliography.
* Using BibTeX::        Automatic generation of bibliographies.
@end menu


@node \bibitem
@subsection @code{\bibitem}

@findex \bibitem

Synopsis:
@example
\bibitem[@var{label}]@{@var{cite_key}@}
@end example

The @code{\bibitem} command generates an entry labelled by
@var{label}.  If the @var{label} argument is missing, a number is
automatically generated using the @code{enumi} counter.  The
@var{cite_key} is any sequence of letters, numbers, and punctuation
symbols not containing a comma.

This command writes an entry to the @file{.aux} file containing the
item's @var{cite_key} and label.  When the @file{.aux} file is read by
the @code{\begin@{document@}} command, the item's @code{label} is
associated with @code{cite_key}, causing references to @var{cite_key}
with a @code{\cite} command (see next section) to produce the
associated label.


@node \cite
@subsection @code{\cite}

@findex \cite

Synopsis:

@example
\cite[@var{subcite}]@{@var{keys}
@end example

The @var{keys} argument is a list of one or more citation keys,
separated by commas.  This command generates an in-text citation to
the references associated with @var{keys} by entries in the
@file{.aux} file.

The text of the optional @var{subcite} argument appears after the
citation.  For example, @code{\cite[p.~314]@{knuth@}} might produce
`[Knuth, p.@tie{}314]'.


@node \nocite
@subsection @code{\nocite}
@findex \nocite

@code{\nocite@{key_list@}}

The @code{\nocite} command produces no text, but writes @code{key_list},
which is a list of one or more citation keys, on the @file{.aux} file.


@node Using BibTeX
@subsection Using Bib@TeX{}

@cindex using Bib@TeX{}
@cindex bib@TeX{}, using
@cindex bibliography, creating (automatically)
@findex \bibliographystyle
@findex \bibliography

If you use the Bib@TeX{} program by Oren Patashnik (highly
recommended if you need a bibliography of more than a couple of
titles) to maintain your bibliography, you don't use the
@code{thebibliography} environment (@pxref{thebibliography}). Instead,
you include the lines

@example
\bibliographystyle@{@var{bibstyle}@}
\bibliography@{@var{bibfile1},@var{bibfile2}@}
@end example

The @code{\bibliographystyle} command does not produce any output of
its own.  Rather, it defines the style in which the bibliography will
be produced: @var{bibstyle} refers to a file
@var{bibstyle}@file{.bst}, which defines how your citations will look.
The standard @var{style} names distributed with Bib@TeX{} are:

@table @code
@item alpha
Sorted alphabetically. Labels are formed from name of author and year of
publication.
@item plain
Sorted alphabetically. Labels are numeric.
@item unsrt
Like @code{plain}, but entries are in order of citation.
@item abbrv
Like @code{plain}, but more compact labels.
@end table

In addition, numerous other Bib@TeX{} style files exist tailored to
the demands of various publications.  See
@url{http://mirror.ctan.org/biblio/bibtex/contrib}.

The @code{\bibliography} command is what actually produces the
bibliography.  The argument to @code{\bibliography} refers to files
named @file{@var{bibfile}.bib}, which should contain your database in
Bib@TeX{} format.  Only the entries referred to via @code{\cite} and
@code{\nocite} will be listed in the bibliography.


@node theorem
@section @code{theorem}

@findex theorem @r{environment}
@cindex theorems, typesetting

Synopsis:

@example
\begin@{theorem@}
@var{theorem-text}
\end@{theorem@}
@end example

The @code{theorem} environment produces ``Theorem @var{n}'' in
boldface followed by @var{theorem-text}, where the numbering
possibilities for @var{n} are described under @code{\newtheorem}
(@pxref{\newtheorem}).


@node titlepage
@section @code{titlepage}

@findex titlepage @r{environment}
@cindex making a title page
@cindex title pages, creating

Synopsis:

@example
\begin@{titlepage@}
@var{text}
\end@{titlepage@}
@end example

The @code{titlepage} environment creates a title page, i.e., a page
with no printed page number or heading.  It also causes the following
page to be numbered page one.  Formatting the title page is left to
you.  The @code{\today} command may be useful on title pages
(@pxref{\today}).

You can use the @code{\maketitle} command (@pxref{\maketitle}) to
produce a standard title page without a @code{titlepage} environment.


@node verbatim
@section @code{verbatim}

@findex verbatim @r{environment}
@cindex verbatim text
@cindex simulating typed text
@cindex typed text, simulating
@cindex code, typesetting
@cindex computer programs, typesetting

Synopsis:

@example
\begin@{verbatim@}
@var{literal-text}
\end@{verbatim@}
@end example

The @code{verbatim} environment is a paragraph-making environment in
which @LaTeX{} produces exactly what you type in; for instance the
@code{\} character produces a printed @samp{\}.  It turns @LaTeX{}
into a typewriter with carriage returns and blanks having the same
effect that they would on a typewriter.

The @code{verbatim} uses a monospaced typewriter-like font (@code{\tt}).

@menu
* \verb::       The macro form of the @code{verbatim} environment.
@end menu

@node \verb
@subsection @code{\verb}

@findex \verb
@cindex verbatim text, inline

Synopsis:

@example
\verb@var{char}@var{literal-text}@var{char}
\verb*@var{char}@var{literal-text}@var{char}
@end example

The @code{\verb} command typesets @var{literal-text} as it is input,
including special characters and spaces, using the typewriter
(@code{\tt}) font.  No spaces are allowed between @code{\verb} or
@code{\verb*} and the delimiter @var{char}, which begins and ends the
verbatim text.  The delimiter must not appear in @var{literal-text}.

@cindex visible space
The @code{*}-form differs only in that spaces are printed with a
``visible space'' character.
@tex
(Namely, {\tt\char`\ }.)
@end tex


@node verse
@section @code{verse}

@findex verse @r{environment}
@cindex poetry, an environment for

Synopsis:

@example
\begin@{verse@}
@var{line1} \\
@var{line2} \\
...
\end@{verse@}
@end example

The @code{verse} environment is designed for poetry, though you may find
other uses for it.

@findex \\ @r{for @code{verse}}
The margins are indented on the left and the right, paragraphs are not
indented, and the text is not justified.  Separate the lines of each
stanza with @code{\\}, and use one or more blank lines to separate the
stanzas.


@node Line breaking
@chapter Line breaking
@cindex line breaking
@cindex breaking lines

The first thing @LaTeX{} does when processing ordinary text is to
translate your input file into a sequence of glyphs and spaces.  To
produce a printed document, this sequence must be broken into lines
(and these lines must be broken into pages).

@LaTeX{} usually does the line (and page) breaking for you, but in
some environments, you do the line breaking yourself with the
@code{\\} command, and you can always manually force breaks.

@menu
* \\::                         Start a new line.
* \obeycr & \restorecr::       Make each input line start a new output line.
* \newline::                   Break the line
* \- (hyphenation)::           Insert explicit hyphenation.
* \fussy::                     Be fussy about line breaking.
* \sloppy::                    Be sloppy about line breaking.
* \hyphenation::               Tell @LaTeX{} how to hyphenate a word.
* \linebreak & \nolinebreak::  Forcing & avoiding line breaks.
@end menu


@node \\
@section @code{\\}[*][@var{morespace}]
@findex \\ @r{force line break}
@cindex new line, starting
@cindex line break, forcing

The @code{\\} command tells @LaTeX{} to start a new line.  It has an
optional argument, @var{morespace}, that specifies how much extra
vertical space is to be inserted before the next line.  This can be a
negative amount.

The @code{\\*} command is the same as the ordinary @code{\\} command
except that it tells @LaTeX{} not to start a new page after the line.


@node \obeycr & \restorecr
@section @code{\obeycr} & @code{\restorecr}
@findex \obeycr
@findex \restorecr
@cindex new line, output as input

The @code{\obeycr} command makes a return in the input file
(@samp{^^M}, internally) the same as @code{\\} (followed by
@code{\relax}).  So each new line in the input will also be a new line
in the output.

@code{\restorecr} restores normal line-breaking behavior.


@node \newline
@section @code{\newline}
@findex \newline
@cindex new line, starting (paragraph mode)

The @code{\newline} command breaks the line at the present point, with
no stretching of the text before it.  It can only be used in paragraph
mode.


@node \- (hyphenation)
@section @code{\-} (discretionary hyphen)
@findex \- @r{(hyphenation)}
@cindex hyphenation, forcing

The @code{\-} command tells @LaTeX{} that it may hyphenate the word at
that point.  @LaTeX{} is pretty good at hyphenating, and usually finds
most of the correct hyphenation points, while almost never using an
incorrect one.  The @code{\-} command is used for the exceptional
cases.

When you insert @code{\-} commands in a word, the word will only be
hyphenated at those points and not at any of the hyphenation points
that @LaTeX{} might otherwise have chosen.



@node \fussy
@section @code{\fussy}
@findex \fussy

The declaration @code{\fussy} (which is the default) makes @TeX{}
picky about line breaking.  This usually avoids too much space between
words, at the cost of an occasional overfull box.

This command cancels the effect of a previous @code{\sloppy} command
(@pxref{\sloppy}.


@node \sloppy
@section @code{\sloppy}

The declaration @code{\sloppy} makes @TeX{} less fussy about line
breaking. This will avoid overfull boxes, at the cost of loose
interword spacing.

Lasts until a @code{\fussy} command is issued (@pxref{\fussy}).


@node \hyphenation
@section @code{\hyphenation}
@findex \hyphenation
@cindex hyphenation, defining

Synopsis:

@example
\hyphenation@{@var{word-one} @var{word-two}@}
@end example

The @code{\hyphenation} command declares allowed hyphenation points
with a @code{-} character in the given words.  The words are separated
by spaces.  @TeX{} will only hyphenate if the word matches exactly, no
inflections are tried.  Multiple @code{\hyphenation} commands
accumulate.  Some examples (the default @TeX{} hyphenation patterns
misses the hyphenations in these words):

@example
\hyphenation@{ap-pen-dix col-umns data-base data-bases@}
@end example


@node \linebreak & \nolinebreak
@section @code{\linebreak} & @code{\nolinebreak}
@findex \linebreak
@findex \nolinebreak
@cindex line breaks, forcing
@cindex line breaks, preventing

Synopses:

@example
\linebreak[@var{priority}]
\nolinebreak[@var{priority}]
@end example

By default, the @code{\linebreak} (@code{\nolinebreak}) command forces
(prevents) a line break at the current position.  For
@code{\linebreak}, the spaces in the line are stretched out so that it
extends to the right margin as usual.

With the optional argument @var{priority}, you can convert the command
from a demand to a request.  The @var{priority} must be a number from
0 to@tie{}4.  The higher the number, the more insistent the request.


@node Page breaking
@chapter Page breaking
@cindex page breaking
@cindex breaking pages

@LaTeX{} starts new pages asynchronously, when enough material has
accumulated to fill up a page.  Usually this happens automatically,
but sometimes you may want to influence the breaks.

@menu
* \cleardoublepage::           Start a new right-hand page.
* \clearpage::                 Start a new page.
* \newpage::                   Start a new page.
* \enlargethispage::           Enlarge the current page a bit.
* \pagebreak & \nopagebreak::  Forcing & avoiding page breaks.
@end menu


@node \cleardoublepage
@section @code{\cleardoublepage}

@findex \cleardoublepage
@cindex starting on a right-hand page

The @code{\cleardoublepage} command ends the current page and causes all
figures and tables that have so far appeared in the input to be printed.
In a two-sided printing style, it also makes the next page a right-hand
(odd-numbered) page, producing a blank page if necessary.


@node \clearpage
@section @code{\clearpage}
@findex \clearpage
@cindex flushing floats and starting a page
@cindex starting a new page and clearing floats

The @code{\clearpage} command ends the current page and causes all
figures and tables that have so far appeared in the input to be printed.


@node \newpage
@section @code{\newpage}
@findex \newpage
@cindex new page, starting
@cindex starting a new page

The @code{\newpage} command ends the current page, but does not clear
floats (see @code{\clearpage} above).


@node \enlargethispage
@section @code{\enlargethispage}
@findex \enlargethispage
@cindex enlarge current page

@code{\enlargethispage@{size@}}

@code{\enlargethispage*@{size@}}

Enlarge the @code{\textheight} for the current page by the specified
amount; e.g. @code{\enlargethispage@{\baselineskip@}} will allow one
additional line.

The starred form tries to squeeze the material together on the page as
much as possible. This is normally used together with an explicit
@code{\pagebreak}.


@node \pagebreak & \nopagebreak
@section @code{\pagebreak} & @code{\nopagebreak}
@findex \pagebreak
@findex \nopagebreak
@cindex page break, forcing
@cindex page break, preventing

Synopses:

@example
\pagebreak[@var{priority}]
\nopagebreak[@var{priority}]
@end example

By default, the @code{\pagebreak} (@code{\nopagebreak}) command forces
(prevents) a page break at the current position.  With
@code{\pagebreak}, the vertical space on the page is stretched out
where possible so that it extends to the normal bottom margin.

With the optional argument @var{priority}, you can convert the
@code{\pagebreak} command from a demand to a request.  The number must
be a number from 0 to@tie{}4.  The higher the number, the more
insistent the request is.


@node Footnotes
@chapter Footnotes
@cindex footnotes, creating

Footnotes can be produced in one of two ways.  They can be produced
with one command, the @code{\footnote} command.  They can also be
produced with two commands, the @code{\footnotemark} and the
@code{\footnotetext} commands.

@menu
* \footnote::           Insert a footnote.
* \footnotemark::       Insert footnote mark only.
* \footnotetext::       Insert footnote text only.
* Symbolic footnotes::  Using symbols instead of numbers for footnotes.
* Footnote parameters:: Parameters for footnote formatting.
@end menu


@node \footnote
@section @code{\footnote}
@findex \footnote

Synopsis:

@example
\footnote[@var{number}]@{@var{text}@}
@end example

The @code{\footnote} command places the numbered footnote @var{text}
at the bottom of the current page.  The optional argument @var{number}
changes the default footnote number.

This command can only be used in outer paragraph mode; i.e., you
cannot use it in sectioning commands like @code{\chapter}, in figures,
tables or in a @code{tabular} environment.  (See following sections.)
@c xx mention packages that fix this


@node \footnotemark
@section @code{\footnotemark}
@findex \footnotemark

With no optional argument, the @code{\footnotemark} command puts the
current footnote number in the text.  This command can be used in
inner paragraph mode.  You give the text of the footnote separately,
with the @code{\footnotetext} command.

This command can be used to produce several consecutive footnote
markers referring to the same footnote with

@example
\footnotemark[\value@{footnote@}]
@end example

@noindent
after the first @code{\footnote} command.


@node \footnotetext
@section @code{\footnotetext}
@findex \footnotetext

Synopsis:

@example
\footnotetext[@var{number}]@{@var{text}@}
@end example

The @code{\footnotetext} command places @var{text} at the bottom of
the page as a footnote.  This command can come anywhere after the
@code{\footnotemark} command.  The @code{\footnotetext} command must
appear in outer paragraph mode.

The optional argument @var{number} changes the default footnote number.


@node Symbolic footnotes
@section Symbolic footnotes

@cindex footnotes, symbolic instead of numbered
If you want to use symbols for footnotes, rather than increasing
numbers, redefine @code{\thefootnote} like this:

@example
\renewcommand@{\thefootnote@}@{\fnsymbol@{footnote@}@}
@end example

@findex \fnsymbol@r{, and footnotes}
@findex \@@fnsymbol
The @code{\fnsymbol} command produces a predefined series of symbols
(@pxref{\alph \Alph \arabic \roman \Roman \fnsymbol}).  If you want to
use a different symbol as your footnote mark, you'll need to also
redefine @code{\@@fnsymbol}.


@node Footnote parameters
@section Footnote parameters

@cindex footnote parameters
@cindex parameters, for footnotes

@ftable @code
@item \footnoterule
Produces the rule separating the main text on a page from the page's
footnotes.  Default dimensions: @code{0.4pt} thick (or wide), and
@code{0.4\columnwidth} long in the standard document classes (except
@code{slides}, where it does not appear).

@item \footnotesep
The height of the strut placed at the beginning of the footnote.  By
default, this is set to the normal strut for @code{\footnotesize}
fonts (@pxref{Font sizes}), therefore there is no extra space between
footnotes.  This is @samp{6.65pt} for @samp{10pt}, @samp{7.7pt} for
@samp{11pt}, and @samp{8.4pt} for @samp{12pt}.

@end ftable


@node Definitions
@chapter Definitions
@cindex definitions

@LaTeX{} has support for making new commands of many different kinds.

@c xx everything in this chapter needs examples.

@menu
* \newcommand & \renewcommand::         (Re)define a new command.
* \newcounter::                         Define a new counter.
* \newlength::                          Define a new length.
* \newsavebox::                         Define a new box.
* \newenvironment & \renewenvironment:: Define a new environment.
* \newtheorem::                         Define a new @code{theorem}-like environment.
* \newfont::                            Define a new font name.
* \protect::                            Using tricky commands.
@end menu


@node \newcommand & \renewcommand
@section @code{\newcommand} & @code{\renewcommand}
@findex \newcommand
@cindex commands, defining new ones
@cindex defining a new command
@cindex new commands, defining

@code{\newcommand} and @code{\renewcommand} define and redefine a
command, respectively.  Synopses:

@example
  \newcommand[*]@{@var{cmd}@}[@var{nargs}][@var{optargval}]@{@var{defn}@}
\renewcommand[*]@{@var{cmd}@}[@var{nargs}][@var{optargval}]@{@var{defn}@}
@end example

@table @var
@item @code{*}
@cindex *-form of defining new commands
The *-form of these commands requires that the arguments not contain
multiple paragraphs of text (not @code{\long}, in plain @TeX{} terms).

@item cmd
The command name, beginning with @code{\}.  For @code{\newcommand}, it
must not be already defined and must not begin with @code{\end}; for
@code{\renewcommand}, it must already be defined.

@item nargs
An optional integer from 1 to 9 specifying the number of arguments
that the command will take.  The default is for the command to have no
arguments.

@item optargval
If this optional parameter is present, it means that the first
argument of command @var{cmd} is optional and its default value (i.e.,
if it is not specified in the call) is @var{optarg}.  In otherwise,
when calling the macro, if no @code{[@var{value}]} is given after
@code{@var{cmd}}---which is different from having @code{[]} for an
empty @var{value}---then string @samp{@var{optargval}} becomes the
value of @code{#1} within @var{defn} when the macro is expanded.

@item defn
The text to be substituted for every occurrence of @code{cmd}; a
construct of the form @code{#@var{n}} in @var{defn} is replaced by the
text of the @var{n}th argument.

@end table

@c xx \providecommand, * form (non-\long)

@node \newcounter
@section @code{\newcounter}
@findex \newcounter
@cindex counters, defining new

Synopsis:

@example
\newcounter@{@var{countername}@}[@var{supercounter}]
@end example

The @code{\newcounter} command defines a new counter named @var{countername}.
The new counter is initialized to zero.

Given the optional argument @code{[@var{super}]}, @var{countername}
will be reset whenever the counter named @var{supercounter} is incremented.

@xref{Counters}, for more information about counters.


@node \newlength
@section @code{\newlength}
@findex \newlength
@cindex lengths, defining new

Synopsis:

@example
\newlength@{\@var{arg}@}
@end example

The @code{\newlength} command defines the mandatory argument as a
@dfn{length} command with a value of zero.  The argument must
be a control sequence, as in @code{\newlength@{\foo@}}.  An error
occurs if @code{\foo} is already defined.

@xref{Lengths}, for how to set the new length to a nonzero value, and
for more information about lengths in general.


@node \newsavebox
@section @code{\newsavebox}
@findex \newsavebox

Synopsis:

@example
\newsavebox@{@var{cmd}@}
@end example

Defines @code{\@var{cmd}}, which must be a command name not already
defined, to refer to a new bin for storing boxes.


@node \newenvironment & \renewenvironment
@section @code{\newenvironment} & @code{\renewenvironment}
@findex \newenvironment
@findex \renewenvironment
@cindex environments, defining
@cindex defining new environments
@cindex redefining environments

Synopses:

@example
  \newenvironment[*]@{@var{env}@}[@var{nargs}][@var{default}]@{@var{begdef}@}@{@var{enddef}@}
\renewenvironment[*]@{@var{env}@}[@var{nargs}]@{@var{begdef}@}@{@var{enddef}@}
@end example

These commands define or redefine an environment @var{env}, that is,
@code{\begin@{@var{env}@} @dots{} \end@{@var{env}@}}.

@table @var
@item @code{*}
@cindex *-form of environment commands
The *-form of these commands requires that the arguments (not the
contents of the environment) not contain multiple paragraphs of text.

@item env
The name of the environment.  For @code{\newenvironment}, @var{env}
must not be an existing environment, and the command @code{\@var{env}}
must be undefined.  For @code{\renewenvironment}, @var{env} must be
the name of an existing environment.

@item nargs
An integer from 1 to 9 denoting the number of arguments of
the newly-defined environment.  The default is no arguments.

@item default
If this is specified, the first argument is optional, and @var{default}
gives the default value for that argument.

@item begdef
The text expanded at every occurrence of @code{\begin@{@var{env}@}}; a
construct of the form @code{#@var{n}} in @var{begdef} is replaced by
the text of the @var{n}th argument.

@item enddef
The text expanded at every occurrence of @code{\end@{@var{env}@}}.  It
may not contain any argument parameters.

@end table


@node \newtheorem
@section @code{\newtheorem}
@findex \newtheorem
@cindex theorems, defining
@cindex defining new theorems

@example
\newtheorem@{@var{newenv}@}@{@var{label}@}[@var{within}]
\newtheorem@{@var{newenv}@}[@var{numbered_like}]@{@var{label}@}
@end example

This command defines a theorem-like environment.  Arguments:

@table @var
@item newenv
The name of the environment to be defined; must not be the name of an
existing environment or otherwise defined.

@item label
The text printed at the beginning of the environment, before the
number. For example, @samp{Theorem}.

@item numbered_like
(Optional.)  The name of an already defined theorem-like environment;
the new environment will be numbered just like @var{numbered_like}.

@item within
(Optional.)  The name of an already defined counter, a sectional unit.
The new theorem counter will be reset at the same time as the
@var{within} counter.

@end table

At most one of @var{numbered_like} and @var{within} can be specified,
not both.


@node \newfont
@section @code{\newfont}
@findex \newfont
@cindex fonts, new commands for
@cindex defining new fonts

Synopsis:

@example
\newfont@{@var{cmd}@}@{@var{fontname}@}
@end example

Defines a control sequence @code{\@var{cmd}}, which must not already
be defined, to make @var{fontname} be the current font.  The file
looked for on the system is named @file{@var{fontname}.tfm}.

This is a low-level command for setting up to use an individual font.
More commonly, fonts are defined in families through @file{.fd} files.


@node \protect
@section @code{\protect}
@findex \protect

@cindex fragile commands
@cindex moving arguments
Footnotes, line breaks, any command that has an optional argument, and
many more are so-called @dfn{fragile} commands.  When a fragile
command is used in certain contexts, called @dfn{moving arguments}, it
must be preceded by @code{\protect}.  In addition, any fragile
commands within the arguments must have their own @code{\protect}.

Some examples of moving arguments are @code{\caption}
(@pxref{figure}), @code{\thanks} (@pxref{\maketitle}), and
@-expressions in @code{tabular} and @code{array} environments
(@pxref{tabular}).

@cindex robust commands
Commands which are not fragile are called @dfn{robust}.  They must not
be preceded by @code{\protect}.

See also:

@smallexample
@exdent @url{http://www-h.eng.cam.ac.uk/help/tpl/textprocessing/teTeX/latex/latex2e-html/fragile.html}
@exdent @url{http://www.tex.ac.uk/cgi-bin/texfaq2html?label=protect}
@end smallexample

@c xx really need examples.


@node Counters
@chapter Counters
@cindex counters, a list of
@cindex variables, a list of

Everything @LaTeX{} numbers for you has a counter associated with
it. The name of the counter is the same as the name of the environment
or command that produces the number, except with no @code{\}.
(@code{enumi}--@code{enumiv} are used for the nested enumerate
environment.)  Below is a list of the counters used in @LaTeX{}'s
standard document classes to control numbering.

@example
part            paragraph       figure          enumi
chapter         subparagraph    table           enumii
section         page            footnote        enumiii
subsection      equation        mpfootnote      enumiv
subsubsection
@end example

@menu
* \alph \Alph \arabic \roman \Roman \fnsymbol::  Print value of a counter.
* \usecounter::         Use a specified counter in a list environment.
* \value::              Use the value of a counter in an expression.
* \setcounter::         Set the value of a counter.
* \addtocounter::       Add a quantity to a counter.
* \refstepcounter::     Add to counter, resetting subsidiary counters.
* \stepcounter::        Add to counter, resetting subsidiary counters.
* \day \month \year::   Numeric date values.
@end menu


@node \alph \Alph \arabic \roman \Roman \fnsymbol
@section @code{\alph \Alph \arabic \roman \Roman \fnsymbol}: Printing counters

All of these commands take a single counter as an argument, for
instance, @code{\alph@{enumi@}}.

@ftable @code
@item \alph
prints @var{counter} using lowercase letters: `a', `b', @enddots{}

@item \Alph
uses uppercase letters: `A', `B', @enddots{}

@item \arabic
uses Arabic numbers: `1', `2', @enddots{}

@item \roman
uses lowercase roman numerals: `i', `ii', @enddots{}

@item \Roman
uses uppercase roman numerals: `I', `II', @enddots{}

@item \fnsymbol
prints the value of @var{counter} in a specific sequence of nine
symbols (conventionally used for labeling footnotes).  The value of
@var{counter} must be between@tie{}1 and@tie{}9, inclusive.

Here are the symbols (as Unicode code points in ASCII output):

@display
asterisk(*) dagger(@U{2021}) ddagger(@U{2021})
section-sign(@U{00A7}) paragraph-sign(@U{00B6}) parallel(@U{2225})
double-asterisk(**) double-dagger(@U{2021}@U{2021}) double-ddagger(@U{2021}@U{2021})
@end display

@end ftable


@node \usecounter
@section @code{\usecounter@{@var{counter}@}}
@findex \usecounter
@cindex list items, specifying counter
@cindex numbered items, specifying counter

Synopsis:

@example
\usecounter@{@var{counter}@}
@end example

The @code{\usecounter} command is used in the second argument of the
@code{list} environment to specify @var{counter} to be used to number
the list items.


@node \value
@section @code{\value@{@var{counter}@}}
@findex \value
@cindex counters, getting value of

Synopsis:

@example
\value@{@var{counter}@}
@end example

The @code{\value} command produces the value of @var{counter}.  It can
be used anywhere @LaTeX{} expects a number, for example:

@example
\setcounter@{myctr@}@{3@}
\addtocounter@{myctr@}@{1@}
\hspace@{\value@{myctr@}\parindent@}
@end example


@node \setcounter
@section @code{\setcounter@{@var{counter}@}@{@var{value}@}}
@findex \setcounter
@cindex counters, setting
@cindex setting counters

Synopsis:

@example
\setcounter@{@var{counter}@}@{@var{value}@}
@end example

The @code{\setcounter} command sets the value of @var{counter} to the
@var{value} argument.


@node \addtocounter
@section @code{\addtocounter@{@var{counter}@}@{@var{value}@}}
@findex \addtocounter

The @code{\addtocounter} command increments @var{counter} by the
amount specified by the @var{value} argument, which may be negative.


@node \refstepcounter
@section @code{\refstepcounter@{@var{counter}@}}
@findex \refstepcounter

The @code{\refstepcounter} command works in the same way as
@code{\stepcounter} @xref{\stepcounter}, except it also defines the
current @code{\ref} value to be the result of @code{\thecounter}.


@node \stepcounter
@section @code{\stepcounter@{@var{counter}@}}
@findex \stepcounter

The @code{\stepcounter} command adds one to @var{counter} and
resets all subsidiary counters.


@node \day \month \year
@section @code{\day \month \year}: Predefined counters
@findex \day
@findex \month
@findex \year

@LaTeX{} defines counters for the day of the month (@code{\day},
1--31), month of the year (@code{\month}, 1--12), and year
(@code{\year}, Common Era).  When @TeX{} starts up, they are
set to the current values on the system where @TeX{} is running.  They
are not updated as the job progresses.

The related command @code{\today} produces a string representing the
current day (@pxref{\today}).


@node Lengths
@chapter Lengths
@cindex lengths, defining and using

A @code{length} is a measure of distance.  Many @LaTeX{} commands take a
length as an argument.

@menu
* \setlength::          Set the value of a length.
* \addtolength::        Add a quantity to a length.
* \settodepth::         Set a length to the depth of something.
* \settoheight::        Set a length to the height of something.
* \settowidth::         Set a length to the width of something.
* Predefined lengths::  Lengths that are, like, predefined.
@end menu


@node \setlength
@section @code{\setlength@{\@var{len}@}@{@var{value}@}}
@findex \setlength
@cindex lengths, setting

The @code{\setlength} sets the value of @var{\len} to the @var{value}
argument, which can be expressed in any units that @LaTeX{}
understands, i.e., inches (@code{in}), millimeters (@code{mm}), points
(@code{pt}), big points (@code{bp}, etc.


@node \addtolength
@section \addtolength@{@var{\len}@}@{@var{amount}@}
@findex \addtolength
@cindex lengths, adding to

The @code{\addtolength} command increments a ``length command''
@var{\len} by the amount specified in the @var{amount} argument, which
may be negative.


@node \settodepth
@section @code{\settodepth}
@findex \settodepth

@code{\settodepth@{\gnat@}@{text@}}

The @code{\settodepth} command sets the value of a @code{length} command
equal to the depth of the @code{text} argument.


@node \settoheight
@section @code{\settoheight}
@findex \settoheight

@code{\settoheight@{\gnat@}@{text@}}

The @code{\settoheight} command sets the value of a @code{length} command
equal to the height of the @code{text} argument.



@node \settowidth
@section @code{\settowidth@{\@var{len}@}@{@var{text}@}}
@findex \settowidth

The @code{\settowidth} command sets the value of the command @var{\len}
to the width of the @var{text} argument.


@node Predefined lengths
@section Predefined lengths
@cindex lengths, predefined
@cindex predefined lengths

@code{\width}
@findex \width

@code{\height}
@findex \height

@code{\depth}
@findex \depth

@code{\totalheight}
@findex \totalheight

These length parameters can be used in the arguments of the box-making
commands (@pxref{Boxes}).  They specify the natural width, etc., of
the text in the box. @code{\totalheight} equals @code{\height} +
@code{\depth}. To make a box with the text stretched to double the
natural size, e.g., say

@code{\makebox[2\width]@{Get a stretcher@}}


@node Making paragraphs
@chapter Making paragraphs
@cindex making paragraphs
@cindex paragraphs

A paragraph is ended by one or more completely blank lines---lines not
containing even a @code{%}.  A blank line should not appear where a new
paragraph cannot be started, such as in math mode or in the argument of
a sectioning command.

@menu
* \indent::        Indent this paragraph.
* \noindent::      Do not indent this paragraph.
* \parskip::       Space added before paragraphs.
* Marginal notes:: Putting remarks in the margin.
@end menu


@node \indent
@section @code{\indent}
@findex \indent
@findex \parindent
@cindex indent, forcing

@code{\indent} produces a horizontal space whose width equals the
width of the @code{\parindent} length, the normal paragraph
indentation.  It is used to add paragraph indentation where it would
otherwise be suppressed.

The default value for @code{\parindent} is @code{1em} in two-column
mode, otherwise @code{15pt} for @code{10pt} documents, @code{17pt} for
@code{11pt}, and @code{1.5em} for @code{12pt}.


@node \noindent
@section @code{\noindent}
@findex \noindent
@cindex indent, suppressing

When used at the beginning of the paragraph, @code{\noindent}
suppresses any paragraph indentation.  It has no effect when used in
the middle of a paragraph.


@node \parskip
@section @code{\parskip}
@findex \parskip
@cindex vertical space before paragraphs

@code{\parskip} is a rubber length defining extra vertical space added
before each paragraph.  The default is @code{0pt plus1pt}.


@node Marginal notes
@section Marginal notes
@cindex marginal notes
@cindex notes in the margin
@cindex remarks in the margin
@findex \marginpar

Synopsis:

@example
\marginpar[@var{left}]@{@var{right}@}
@end example

The @code{\marginpar} command creates a note in the margin.  The first
line of the note will have the same baseline as the line in the text
where the @code{\marginpar} occurs.

When you only specify the mandatory argument @var{right}, the text
will be placed

@itemize @bullet
@item
in the right margin for one-sided layout;
@item
in the outside margin for two-sided layout;
@item
in the nearest margin for two-column layout.
@end itemize

@findex \reversemarginpar
@findex \normalmarginpar
The command @code{\reversemarginpar} places subsequent marginal notes
in the opposite (inside) margin.  @code{\normalmarginpar} places them
in the default position.

When you specify both arguments, @var{left} is used for the left
margin, and @var{right} is used for the right margin.

The first word will normally not be hyphenated; you can enable
hyphenation there by beginning the node with @code{\hspace@{0pt@}}.

These parameters affect the formatting of the note:

@ftable @code
@item \marginparpush
Minimum vertical space between notes; default @samp{7pt} for
@samp{12pt} documents, @samp{5pt} else.

@item \marginparsep
Horizontal space between the main text and the note; default
@samp{11pt} for @samp{10pt} documents, @samp{10pt} else.

@item \marginparwidth
Width of the note itself; default for a one-sided @samp{10pt} document
is @samp{90pt}, @samp{83pt} for @samp{11pt}, and @samp{68pt} for
@samp{12pt}; @samp{17pt} more in each case for a two-sided document.
In two column mode, the default is @samp{48pt}.

@end ftable

The standard @LaTeX{} routine for marginal notes does not prevent
notes from falling off the bottom of the page.
@c  @TeX{} FAQ entry on this topic (xx when there):
@c @url{http://www.tex.ac.uk/cgi-bin/texfaq2html?label=marginparside}.
@c (+marginfix)


@node Math formulas
@chapter Math formulas
@cindex math formulas
@cindex formulas, math
@cindex math mode, entering

@findex math @r{environment}
@findex displaymath @r{environment}
@findex equation @r{environment}
There are three environments that put @LaTeX{} in math mode:

@table @code
@item math
For formulas that appear right in the text.
@item displaymath
For formulas that appear on their own line.
@item equation
The same as the displaymath environment except that it adds an equation
number in the right margin.
@end table

@findex \(
@findex \)
@findex \[
@findex \]
The @code{math} environment can be used in both paragraph and LR mode,
but the @code{displaymath} and @code{equation} environments can be used
only in paragraph mode.  The @code{math} and @code{displaymath}
environments are used so often that they have the following short forms:

@example
\(...\)   @r{instead of}   \begin@{math@}...\end@{math@}
\[...\]   @r{instead of}   \begin@{displaymath@}...\end@{displaymath@}
@end example

@findex $
In fact, the @code{math} environment is so common that it has an even
shorter form:

@example
$ ... $   @r{instead of}   \(...\)
@end example

@findex \boldmath
@findex \unboldmath
The @code{\boldmath} command changes math letters and symbols to be in
a bold font.  It is used @emph{outside} of math mode.  Conversely, the
@code{\unboldmath} command changes math glyphs to be in a normal font;
it too is used @emph{outside} of math mode.

@c xx own section? Math fonts?
@findex \displaystyle
The @code{\displaystyle} declaration forces the size and style of the
formula to be that of @code{displaymath}, e.g., with limits above and
below summations.  For example
@example
$\displaystyle \sum_@{n=0@}^\infty x_n $
@end example

@c xx see also \cal, \mathcal

@menu
* Subscripts & superscripts::   Also known as exponent or index.
* Math symbols::                Various mathematical squiggles.
* Math functions::              Math function names like sin and exp.
* Math accents::                Accents in math.
* Spacing in math mode::        Thick, medium, thin and negative spaces.
* Math miscellany::             Stuff that doesn't fit anywhere else.
@end menu


@node Subscripts & superscripts
@section Subscripts & superscripts
@cindex superscript
@cindex subscript
@cindex exponent
@findex _
@findex ^

To get an expression @i{exp} to appear as a subscript, you just type
@code{_@{}@i{exp}@code{@}}.  To get @i{exp} to appear as a
superscript, you type @code{^@{}@i{exp}@code{@}}. @LaTeX{} handles
superscripted superscripts and all of that stuff in the natural way.
It even does the right thing when something has both a subscript and a
superscript.


@node Math symbols
@section Math symbols
@cindex math symbols
@cindex symbols, math
@cindex greek letters

@LaTeX{} provides almost any mathematical symbol you're likely to
need. The commands for generating them can be used only in math mode.
For example, if you include @code{$\pi$} in your source, you will get
the pi symbol (@math{\pi}) in your output.

@ftable @code
@item \|
@math{\|}

@item \aleph
@math{\aleph}

@item \alpha
@math{\alpha}

@item \amalg
@math{\amalg} (binary operation)

@item \angle
@math{\angle}

@item \approx
@math{\approx} (relation)

@item \ast
@math{\ast} (binary operation)

@item \asymp
@math{\asymp} (relation)

@item \backslash
\ (delimiter)

@item \beta
@math{\beta}

@item \bigcap
@math{\bigcap}

@item \bigcirc
@math{\bigcirc} (binary operation)

@item \bigcup
@math{\bigcup}

@item \bigodot
@math{\bigodot}

@item \bigoplus
@math{\bigoplus}

@item \bigotimes
@math{\bigotimes}

@item \bigtriangledown
@math{\bigtriangledown} (binary operation)

@item \bigtriangleup
@math{\bigtriangleup} (binary operation)

@item \bigsqcup
@math{\bigsqcup}

@item \biguplus
@math{\biguplus}

@item \bigcap
@math{\bigvee}

@item \bigwedge
@math{\bigwedge}

@item \bot
@math{\bot}

@item \bowtie
@math{\bowtie} (relation)

@item \Box
(square open box symbol) @c xx not in plain

@item \bullet
@cindex bullet symbol
@math{\bullet} (binary operation)

@item \cap
@math{\cap} (binary operation)

@item \cdot
@math{\cdot} (binary operation)

@item \chi
@math{\chi}

@item \circ
@math{\circ} (binary operation)

@item \clubsuit
@math{\clubsuit}

@item \cong
@math{\cong} (relation)

@item \coprod
@math{\coprod}

@item \cup
@math{\cup} (binary operation)

@item \dagger
@math{\dagger} (binary operation)

@item \dashv
@math{\dashv} (relation)

@item \ddagger
@math{\dagger} (binary operation)

@item \Delta
@math{\Delta}

@item \delta
@math{\delta}

@item \Diamond
bigger @math{\diamond} @c xx not in plain

@item \diamond
@math{\diamond} (binary operation)

@item \diamondsuit
@math{\diamondsuit}

@item \div
@math{\div} (binary operation)

@item \doteq
@math{\doteq} (relation)

@item \downarrow
@math{\downarrow} (delimiter)

@item \Downarrow
@math{\Downarrow} (delimiter)

@item \ell
@math{\ell}

@item \emptyset
@math{\emptyset}

@item \epsilon
@math{\epsilon}

@item \equiv
@math{\equiv} (relation)

@item \eta
@math{\eta}

@item \exists
@math{\exists}

@item \flat
@math{\flat}

@item \forall
@math{\forall}

@item \frown
@math{\frown} (relation)

@item \Gamma
@math{\Gamma}

@item \gamma
@math{\gamma}

@item \ge
@math{\ge}

@item \geq
@math{\geq} (relation)

@item \gets
@math{\gets}

@item \gg
@math{\gg} (relation)

@item \hbar
@math{\hbar}

@item \heartsuit
@math{\heartsuit}

@item \hookleftarrow
@math{\hookleftarrow}

@item \hookrightarrow
@math{\hookrightarrow}

@item \iff
@math{\iff}

@item \Im
@math{\Im}

@item \in
@math{\in} (relation)

@item \infty
@math{\infty}

@item \int
@math{\int}

@item \iota
@math{\iota}

@item \Join
condensed bowtie symbol (relation) @c xx not in plain

@item \kappa
@math{\kappa}

@item \Lambda
@math{\Lambda}

@item \lambda
@math{\lambda}

@item \land
@math{\land}

@item \langle
@math{\langle} (delimiter)

@item \lbrace
@math{\lbrace} (delimiter)

@item \lbrack
@math{\lbrack} (delimiter)

@item \lceil
@math{\lceil} (delimiter)

@item \le
@math{\le}

@item \leadsto
@c xx missing from plain

@item \Leftarrow
@math{\Leftarrow}

@item \leftarrow
@math{\leftarrow}

@item \leftharpoondown
@math{\leftharpoondown}

@item \leftharpoonup
@math{\leftharpoonup}

@item \Leftrightarrow
@math{\Leftrightarrow}

@item \leftrightarrow
@math{\leftrightarrow}

@item \leq
@math{\leq} (relation)

@item \lfloor
@math{\lfloor} (delimiter)

@item \lhd
(left-pointing arrow head) @c xx not in plain

@item \ll
@math{\ll} (relation)

@item \lnot
@math{\lnot}

@item \longleftarrow
@math{\longleftarrow}

@item \longleftrightarrow
@math{\longleftrightarrow}

@item \longmapsto
@math{\longmapsto}

@item \longrightarrow
@math{\longrightarrow}

@item \lor
@math{\lor}

@item \mapsto
@math{\mapsto}

@item \mho
@c xx not in plain

@item \mid
@math{\mid} (relation)

@item \models
@math{\models} (relation)

@item \mp
@math{\mp} (binary operation)

@item \mu
@math{\mu}

@item \nabla
@math{\nabla}

@item \natural
@math{\natural}

@item \ne
@math{\ne}

@item \nearrow
@math{\nearrow}

@item \neg
@math{\neg}

@item \neq
@math{\neq} (relation)

@item \ni
@math{\ni} (relation)

@item \not
Overstrike a following operator with a /, as in @math{\not=}.

@item \notin
@math{\ni}

@item \nu
@math{\nu}

@item \nwarrow
@math{\nwarrow}

@item \odot
@math{\odot} (binary operation)

@item \oint
@math{\oint}

@item \Omega
@math{\Omega}

@item \omega
@math{\omega}

@item \ominus
@math{\ominus} (binary operation)

@item \oplus
@math{\oplus} (binary operation)

@item \oslash
@math{\oslash} (binary operation)

@item \otimes
@math{\otimes} (binary operation)

@item \owns
@math{\owns}

@item \parallel
@math{\parallel} (relation)

@item \partial
@math{\partial}

@item \perp
@math{\perp} (relation)

@item \phi
@math{\phi}

@item \Pi
@math{\Pi}

@item \pi
@math{\pi}

@item \pm
@math{\pm} (binary operation)

@item \prec
@math{\prec} (relation)

@item \preceq
@math{\preceq} (relation)

@item \prime
@math{\prime}

@item \prod
@math{\prod}

@item \propto
@math{\propto} (relation)

@item \Psi
@math{\Psi}

@item \psi
@math{\psi}

@item \rangle
@math{\rangle} (delimiter)

@item \rbrace
@math{\rbrace} (delimiter)

@item \rbrack
@math{\rbrack} (delimiter)

@item \rceil
@math{\rceil} (delimiter)

@item \Re
@math{\Re}

@item \rfloor
@math{\rfloor}

@item \rhd
(binary operation) @c xx not in plain @math{\rhd}

@item \rho
@math{\rho}

@item \Rightarrow
@math{\Rightarrow}

@item \rightarrow
@math{\rightarrow}

@item \rightharpoondown
@math{\rightharpoondown}

@item \rightharpoonup
@math{\rightharpoonup}

@item \rightleftharpoons
@math{\rightleftharpoons}

@item \searrow
@math{\searrow}

@item \setminus
@math{\setminus} (binary operation)

@item \sharp
@math{\sharp}

@item \Sigma
@math{\Sigma}

@item \sigma
@math{\sigma}

@item \sim
@math{\sim} (relation)

@item \simeq
@math{\simeq} (relation)

@item \smallint
@math{\smallint}

@item \smile
@math{\smile} (relation)

@item \spadesuit
@math{\spadesuit}

@item \sqcap
@math{\sqcap} (binary operation)

@item \sqcup
@math{\sqcup} (binary operation)

@item \sqsubset
(relation) @c not in plain (@math{\sqsubset})

@item \sqsubseteq
@math{\sqsubseteq} (relation)

@item \sqsupset
(relation) @c not in plain (@math{\sqsupset})

@item \sqsupseteq
@math{\sqsupseteq} (relation)

@item \star
@math{\star} (binary operation)

@item \subset
@math{\subset} (relation)

@item \subseteq
@math{\subseteq} (relation)

@item \succ
@math{\succ} (relation)

@item \succeq
@math{\succeq} (relation)

@item \sum
@math{\sum}

@item \supset
@math{\supset} (relation)

@item \supseteq
@math{\supseteq} (relation)

@item \surd
@math{\surd}

@item \swarrow
@math{\swarrow}

@item \tau
@math{\tau}

@item \theta
@math{\theta}

@item \times
@math{\times} (binary operation)

@item \to
@math{\to}

@item \top
@math{\top}

@item \triangle
@math{\triangle}

@item \triangleleft
@math{\triangleleft} (binary operation)

@item \triangleright
@math{\triangleright} (binary operation)

@item \unlhd
left-pointing arrowhead with line under (binary operation) @c not in plain

@item \unrhd
right-pointing arrowhead with line under (binary operation) @c not in plain

@item \Uparrow
@math{\Uparrow} (delimiter)

@item \uparrow
@math{\uparrow} (delimiter)

@item \Updownarrow
@math{\Updownarrow} (delimiter)

@item \updownarrow
@math{\updownarrow} (delimiter)

@item \uplus
@math{\uplus} (binary operation)

@item \Upsilon
@math{\Upsilon}

@item \upsilon
@math{\upsilon}

@item \varepsilon
@math{\varepsilon}

@item \varphi
@math{\varphi}

@item \varpi
@math{\varpi}

@item \varrho
@math{\varrho}

@item \varsigma
@math{\varsigma}

@item \vartheta
@math{\vartheta}

@item \vdash
@math{\vdash} (relation)

@item \vee
@math{\vee} (binary operation)

@item \Vert
@math{\Vert} (delimiter)

@item \vert
@math{\vert} (delimiter)

@item \wedge
@math{\wedge} (binary operation)

@item \wp
@math{\wp}

@item \wr
@math{\wr} (binary operation)

@item \Xi
@math{\Xi}

@item \xi
@math{\xi}

@item \zeta
@math{\zeta}

@end ftable


@node Math functions
@section Math functions
@cindex math functions
@cindex functions, math

These commands produce roman function names in math mode with proper
spacing.

@ftable @code
@item \arccos
@math{\arccos}

@item \arcsin
@math{\arcsin}

@item \arctan
@math{\arctan}

@item \arg
@math{\arg}

@item \bmod
Binary modulo operator (@math{x \bmod y})

@item \cos
@math{\cos}

@item \cosh
@math{\cosh}

@item \cot
@math{\cos}

@item \coth
@math{\cosh}

@item \csc
@math{\csc}

@item \deg
@math{\deg}

@item \det
@math{\deg}

@item \dim
@math{\dim}

@item \exp
@math{\exp}

@item \gcd
@math{\gcd}

@item \hom
@math{\hom}

@item \inf
@math{\inf}

@item \ker
@math{\ker}

@item \lg
@math{\lg}

@item \lim
@math{\lim}

@item \liminf
@math{\liminf}

@item \limsup
@math{\limsup}

@item \ln
@math{\ln}

@item \log
@math{\log}

@item \max
@math{\max}

@item \min
@math{\min}

@item \pmod
parenthesized modulus, as in (@math{\pmod 2^n - 1})

@item \Pr
@math{\Pr}

@item \sec
@math{\sec}

@item \sin
@math{\sin}

@item \sinh
@math{\sinh}

@item \sup
sup
@c don't try to use \sup since that turned into a Texinfo command
@c and it's not worth hassling with different versions when it's
@c just three roman letters anyway.

@item \tan
@math{\tan}

@item \tanh
@math{\tanh}

@end ftable


@node Math accents
@section Math accents
@cindex math accents
@cindex accents, mathematical

@LaTeX{} provides a variety of commands for producing accented letters
in math.  These are different from accents in normal text
(@pxref{Accents}).

@ftable @code
@item \acute
@cindex acute accent, math
Math acute accent: @math{\acute{x}}.

@item \bar
@cindex bar-over accent, math
@cindex macron accent, math
Math bar-over accent: @math{\bar{x}}.

@item \breve
@cindex breve accent, math
Math breve accent: @math{\breve{x}}.

@item \check
@cindex check accent, math
@cindex h@'a@v{c}ek accent, math
Math h@'a@v{c}ek (check) accent: @math{\check{x}}.

@item \ddot
@cindex double dot accent, math
Math dieresis accent: @math{\ddot{x}}.

@item \dot
@cindex overdot accent, math
@cindex dot over accent, math
Math dot accent: @math{\dot{x}}.

@item \grave
@cindex grave accent, math
Math grave accent: @math{\grave{x}}.

@item \hat
@cindex hat accent, math
@cindex circumflex accent, math
Math hat (circumflex) accent: @math{\hat{x}}.

@item \imath
@cindex dotless i, math
Math dotless i.

@item \jmath
@cindex dotless j, math
Math dotless j.

@item \mathring
@cindex ring accent, math
Math ring accent: @ringaccent{x}.  @c don't bother implementing in texinfo

@item \tilde
@cindex tilde accent, math
Math tilde accent: @math{\tilde{x}}.

@item \vec
@cindex vector symbol, math
Math vector symbol: @math{\vec{x}}.

@item \widehat
@cindex wide hat accent, math
Math wide hat accent: @math{\widehat{x+y}}.

@item \widehat
@cindex wide tile accent, math
Math wide tilde accent: @math{\widetilde{x+y}}.

@end ftable


@node Spacing in math mode
@section Spacing in math mode
@cindex spacing within math mode
@cindex math mode, spacing

In a @code{math} environment, @LaTeX{} ignores the spaces you type and
puts in the spacing according to the normal rules for mathematics
texts.  If you want different spacing, @LaTeX{} provides the following
commands for use in math mode:

@table @code
@item \;
@findex \;
A thick space (@math{5\over18\,}quad).
@item \:
@itemx \>
@findex \:
@findex \>
Both of these produce a medium space (@math{2\over9\,}quad).
@item \,
@findex \,
A thin space (@math{1\over6\,}quad); not restricted to math mode.
@item \!
A negative thin space (@math{-{1\over6}\,}quad).
@end table


@node Math miscellany
@section Math miscellany
@cindex math miscellany

@ftable @code

@item \*
@cindex discretionary multiplication
@cindex multiplication symbol, discretionary line break
A ``discretionary'' multiplication symbol, at which a line break is
allowed.

@item \cdots
A horizontal ellipsis with the dots raised to the center of the line.
@tex
As in: `$\cdots$'.
@end tex

@item \ddots
A diagonal ellipsis: @math{\ddots}.

@item \frac@{num@}@{den@}
@findex \frac
Produces the fraction @code{num} divided by @code{den}.

@iftex
eg.
@tex
${1}\over{4}$
@end tex
@end iftex

@item \left @var{delim1} ... \right @var{delim2}
@findex \right
@cindex null delimiter
The two delimiters need not match; @samp{.} acts as a null delimiter,
producing no output.  The delimiters are sized according to the math
in between.  Example: @code{\left( \sum_i=1^10 a_i \right]}.

@item \overbrace@{@var{text}@}
Generates a brace over @var{text}.
For example, @math{\overbrace{x+\cdots+x}^{k \rm\;times}}.

@item \overline@{@var{text}@}
Generates a horizontal line over @var{tex}.
For example, @math{\overline{x+y}}.

@item \sqrt[@var{root}]@{arg@}
Produces the representation of the square root of @var{arg}.  The
optional argument @var{root} determines what root to produce.  For
example, the cube root of @code{x+y} would be typed as
@code{$\sqrt[3]@{x+y@}$}.
@tex
In @TeX{}, the result looks like this:
$\root 3 \of x+y$.
@end tex

@item \stackrel@{@var{text}@}@{@var{relation}@}
Puts @var{text} above @var{relation}.  For example,
@code{\stackrel@{f@}@{\longrightarrow@}}.
@tex
In @TeX{}, the result looks like this:
$\buildrel f \over \longrightarrow$.
@end tex

@item \underbrace@{math@}
Generates @var{math} with a brace underneath.
@tex
In @TeX{}, the result looks like this:
$\underbrace{x+y+z}_{>\,0}$.
@end tex

@item \underline@{text@}
Causes @var{text}, which may be either math mode or not, to be
underlined.  The line is always below the text, taking account of
descenders.
@tex
In @TeX{}, the result looks like this:
$\underline{xyz}$
@end tex

@item \vdots
@findex \vdots
Produces a vertical ellipsis.
@tex
In @TeX{}, the result looks like this:
$\vdots$.
@end tex

@end ftable


@node Modes
@chapter Modes
@cindex modes
@cindex paragraph mode
@cindex math mode
@cindex left-to-right mode
@cindex LR mode

When @LaTeX{} is processing your input text, it is always in one of three
modes:

@itemize @bullet
@item
Paragraph mode
@item
Math mode
@item
Left-to-right mode, called LR mode for short
@end itemize

Mode changes occur only when entering or leaving an environment, or when
@LaTeX{} is processing the argument of certain text-producing commands.

@dfn{Paragraph mode} is the most common; it's the one @LaTeX{} is in
when processing ordinary text.  In this mode, @LaTeX{} breaks the
input text into lines and breaks the lines into pages.

@LaTeX{} is in @dfn{math mode} when it's generating a mathematical
formula, either displayed math or within a line.

@findex \mbox@r{, and LR mode}
In @dfn{LR mode}, as in paragraph mode, @LaTeX{} considers the output
that it produces to be a string of words with spaces between them.
However, unlike paragraph mode, @LaTeX{} keeps going from left to
right; it never starts a new line in LR mode.  Even if you put a
hundred words into an @code{\mbox}, @LaTeX{} would keep typesetting
them from left to right inside a single box (and then most likely
complain because the resulting box was too wide to fit on the line).
@LaTeX{} is in LR mode when it starts making a box with an
@code{\mbox} command.  You can get it to enter a different mode inside
the box---for example, you can make it enter math mode to put a
formula in the box.

There are also several text-producing commands and environments for
making a box that put @LaTeX{} into paragraph mode.  The box made by
one of these commands or environments will be called a @code{parbox}.
When @LaTeX{} is in paragraph mode while making a box, it is said to
be in ``inner paragraph mode'' (no page breaks).  Its normal paragraph
mode, which it starts out in, is called ``outer paragraph mode''.


@node Page styles
@chapter Page styles
@cindex styles, page
@cindex page styles

The @code{\documentclass} command determines the size and position of
the page's head and foot.  The page style determines what goes in them.

@menu
* \maketitle::          Generate a title page.
* \pagenumbering::      Set the style used for page numbers.
* \pagestyle::		Change the headings/footings style.
* \thispagestyle::      Change the headings/footings style for this page.
@end menu


@node \maketitle
@section @code{\maketitle}
@cindex titles, making
@findex \maketitle

The @code{\maketitle} command generates a title on a separate title
page---except in the @code{article} class, where the title is placed
at the top of the first page.  Information used to produce the title
is obtained from the following declarations:

@ftable @code
@item \author@{@var{name} \and @var{name2}@}
@cindex author, for titlepage
@findex \\ @r{for @code{\author}}
@findex \and @r{for @code{\author}}
The @code{\author} command declares the document author(s), where the
argument is a list of authors separated by @code{\and} commands.  Use
@code{\\} to separate lines within a single author's entry---for
example, to give the author's institution or address.

@item \date@{@var{text}@}
@cindex date, for titlepage
The @code{\date} command declares @var{text} to be the document's
date.  With no @code{\date} command, the current date (@pxref{\today})
is used.

@item \thanks@{@var{text}@}
@cindex thanks, for titlepage
@cindex credit footnote
The @code{\thanks} command produces a @code{\footnote} to the title,
usually used for credit acknowledgements.

@item \title@{@var{text}@}
@cindex title, for titlepage
@findex \\ @r{for @code{\title}}
The @code{\title} command declares @var{text} to be the title of the
document.  Use @code{\\} to force a line break, as usual.

@end ftable


@node \pagenumbering
@section @code{\pagenumbering}
@findex \pagenumbering
@cindex page numbering style

Synopsis:

@example
\pagenumbering@{@var{style}@}
@end example

Specifies the style of page numbers, according to @var{style}; also
resets the page number to 1.  The @var{style} argument is one of
the following:

@table @code
@item arabic
arabic numerals

@item roman
lowercase Roman numerals

@item Roman
uppercase Roman numerals

@item alph
lowercase letters

@item Alph
uppercase letters
@end table


@node \pagestyle
@section @code{\pagestyle}
@findex \pagestyle
@cindex header style
@cindex footer style
@cindex running header and footer style

Synopsis:

@example
\pagestyle@{@var{style}@}
@end example

The @code{\pagestyle} command specifies how the headers and footers
are typeset from the current page onwards.  Values for @var{style}:

@table @code
@item plain
Just a plain page number.

@item empty
Empty headers and footers, e.g., no page numbers.

@item headings
Put running headers on each page.  The document style specifies what
goes in the headers.

@item myheadings
Custom headers, specified via the @code{\markboth} or the
@code{\markright} commands.

@end table

Here are the descriptions of @code{\markboth} and @code{\markright}:

@ftable @code
@item \markboth@{@var{left}@}@{@var{right}@}
Sets both the left and the right heading.  A ``left-hand heading''
(@var{left}) is generated by the last @code{\markboth} command before
the end of the page, while a ``right-hand heading'' (@var{right}) is
generated by the first @code{\markboth} or @code{\markright} that
comes on the page if there is one, otherwise by the last one before
the page.

@item \markright@{@var{right}@}
Sets the right heading, leaving the left heading unchanged.

@end ftable


@node \thispagestyle
@section @code{\thispagestyle@{@var{style}@}}
@findex \thispagestyle

The @code{\thispagestyle} command works in the same manner as the
@code{\pagestyle} command (see previous section) except that it
changes to @var{style} for the current page only.


@node Spaces
@chapter Spaces
@cindex spaces

@LaTeX{} has many ways to produce white (or filled) space.

Another space-producing command is @code{\,} to produce a ``thin''
space (usually 1/6@dmn{quad}).  It can be used in text mode, but is
more often useful in math mode  (@pxref{Spacing in math mode}).

@menu
Horizontal space
* \hspace::             Fixed horizontal space.
* \hfill::              Stretchable horizontal space.
* \SPACE::              Normal interword space.
* \@@::                  Ending a sentence.
* \thinspace::          One-sixth of an em.
* \/::                  Insert italic correction.
* \hrulefill::          Stretchable horizontal rule.
* \dotfill::            Stretchable horizontal dots.

Vertical space
* \addvspace::                    Add arbitrary vertical space if needed.
* \bigskip \medskip \smallskip::  Fixed vertical spaces.
* \vfill::                        Infinitely stretchable vertical space.
* \vspace::                       Add arbitrary vertical space.
@end menu


@node \hspace
@section @code{\hspace}
@findex \hspace

Synopsis:

@example
\hspace[*]@{@var{length}@}
@end example

The @code{\hspace} command adds horizontal space.  The @var{length}
argument can be expressed in any terms that @LaTeX{} understands:
points, inches, etc.  It is a rubber length.  You can add both
negative and positive space with an @code{\hspace} command; adding
negative space is like backspacing.

@LaTeX{} normally removes horizontal space that comes at the beginning
or end of a line.  To preserve this space, use the optional @code{*}
form.


@node \hfill
@section @code{\hfill}
@findex \hfill

@cindex stretch, infinite horizontal
@cindex infinite horizontal stretch
The @code{\hfill} fill command produces a ``rubber length'' which has
no natural space but can stretch or shrink horizontally as far as
needed.

@findex \fill
The @code{\fill} parameter is the rubber length itself (technically,
the glue value @samp{0pt plus1fill}); thus, @code{\hspace\fill} is
equivalent to @code{\hfill}.


@node \SPACE
@section @code{\SPACE}: Normal interword space
@findex \SPACE
@findex \TAB
@findex \NEWLINE

The @code{\ } (space) command produces a normal interword space.  It's
useful after punctuation which shouldn't end a sentence.  For example,
@code{the article in Proc.\ Amer.\ Math\. Soc.\ is fundamental}.  It
is also often used after control sequences, as in @code{\TeX\ is a
nice system.}

In normal circumstances, @code{\}@key{tab} and @code{\}@key{newline}
are equivalent to @code{\ }.


@node \@@
@section @code{\@@}: Force sentence-ending punctuation
@findex \@@
@anchor{\AT}@c old name

The @code{\@@} command makes the following punctuation character end a
sentence even if it normally would not.  This is typically used after
a capital letter.  Here are side-by-side examples with and without
@code{\@@}:

@example
@dots{} in C\@@. Pascal, though @dots{}
@dots{} in C. Pascal, though @dots{}
@end example

@noindent produces

@c Texinfo has different commands, but the result is the same.
@quotation
@dots{} in C@. Pascal, though @dots{}@*
@dots{} in C. Pascal, though @dots{}
@end quotation


@node \thinspace
@section @code{\thinspace}: Insert 1/6@dmn{em}
@findex \thinspace

@code{\thinspace} produces an unbreakable and unstretchable space that
is 1/6 of an em.  This is the proper space to use between nested
quotes, as in '@dmn{}''.@c Abuse @dmn, which is a thin space in Texinfo.


@node \/
@section @code{\/}: Insert italic correction
@findex \/
@cindex italic correction

The @code{\/} command produces an @dfn{italic correction}.  This is a
small space defined by the font designer for a given character,
to avoid the character colliding with whatever follows.  The italic
@i{f} character typically has a large italic correction value.

If the following character is a period or comma, it's not necessary to
insert an italic correction, since those punctuation symbols have a
very small height.  However, with semicolons or colons, as well as
normal letters, it can help. Compare
@tex
{\it f\/: f\/;}
@end tex
@ifnottex
@i{f: f;} (in the @TeX{} output, the `f's are nicely separated)
@end ifnottex
with @i{f: f;}.

When changing fonts with commands such as @code{\textit@{italic
text@}} or @code{@{\itshape italic text@}}, @LaTeX{} will
automatically insert an italic correction if appropriate (@pxref{Font
styles}).

Despite the name, roman characters can also have an italic
correction.  Compare
@tex
pdf\/\TeX{}
@end tex
@ifnottex
pdf@TeX{} (in the @TeX{} output, there is a small space after the `f')
@end ifnottex
with pdf@TeX{}.

There is no concept of italic correction in math mode; spacing is done
in a different way.


@node \hrulefill
@section @code{\hrulefill}
@findex \hrulefill

The @code{\hrulefill} fill command produces a ``rubber length'' which can
stretch or shrink horizontally.  It will be filled with a horizontal
rule.


@node \dotfill
@section @code{\dotfill}

@findex \dotfill

The @code{\dotfill} command produces a ``rubber length'' that fills
with dots instead of just white space.


@c xx undone
@node \addvspace
@section @code{\addvspace}
@findex \addvspace
@cindex vertical space
@cindex space, inserting vertical

@code{\addvspace@{length@}}

The @code{\addvspace} command normally adds a vertical space of height
length.  However, if vertical space has already been added to the same
point in the output by a previous @code{\addvspace} command, then this
command will not add more space than is needed to make the natural
length of the total vertical space equal to @code{length}.


@node \bigskip \medskip \smallskip
@section @code{\bigskip \medskip \smallskip}

These commands produce a given amount of space, specified by the
document class.

@table @code
@item \bigskip
@findex \bigskip
@findex \bigskipamount
The same as @code{\vspace@{\bigskipamount@}}, ordinarily about one line
space, with stretch and shrink (the default for the @code{book} and
@code{article} classes is @code{12pt plus 4pt minus 4pt}).

@item \medskip
@findex \medskip
@findex \medskipamount
The same as @code{\vspace@{\medskipamount@}}, ordinarily about half of
a line space, with stretch and shrink (the default for the @code{book}
and @code{article} classes is @code{6pt plus 2pt minus 2pt}).

@item \smallskip
@findex \smallskip
@findex \smallskipamount
The same as @code{\vspace@{\smallskipamount@}}, ordinarily about a
quarter of a line space, with stretch and shrink (the default for the
@code{book} and @code{article} classes is @code{3pt plus 1pt minus
1pt}).

@end table


@node \vfill
@section @code{\vfill}
@findex \vfill

@cindex stretch, infinite vertical
@cindex infinite vertical stretch

The @code{\vfill} fill command produces a rubber length (glue) which
can stretch or shrink vertically as far as needed.  It's equivalent to
@code{\vspace@{\fill@}} (@pxref{\hfill}).


@node \vspace
@section @code{\vspace[*]@{@var{length}@}}
@findex \vspace

Synopsis:

@example
\vspace[*]@{@var{length}@}
@end example

The @code{\vspace} command adds the vertical space @var{length}, i.e.,
a rubber length.  @var{length} can be negative or positive.

Ordinarily, @LaTeX{} removes vertical space added by @code{\vspace} at
the top or bottom of a page.  With the optional @code{*} argument, the
space is not removed.


@node Boxes
@chapter Boxes

@cindex boxes

All the predefined length parameters (@pxref{Predefined lengths}) can be
used in the arguments of the box-making commands.

@menu
* \mbox::               Horizontal boxes.
* \fbox and \framebox:: Put a frame around a box.
* lrbox::               An environment like @code{\sbox}.
* \makebox::            Box, adjustable position.
* \parbox::             Box with text in paragraph mode.
* \raisebox::           Raise or lower text.
* \savebox::            Like @code{\makebox}, but save the text for later use.
* \sbox::               Like @code{\mbox}, but save the text for later use.
* \usebox::             Print saved text.
@end menu


@node \mbox
@section @code{\mbox@{@var{text@}}}
@findex \mbox

@cindex hyphenation, preventing
The @code{\mbox} command creates a box just wide enough to hold the
text created by its argument.  The @var{text} is not broken into
lines, so it can be used to prevent hyphenation.


@node \fbox and \framebox
@section @code{\fbox} and @code{\framebox}

@findex \fbox
@findex \framebox

Synopses:

@example
\fbox@{@var{text}@}
\framebox[@var{width}][@var{position}]@{@var{text}@}
@end example

The @code{\fbox} and @code{\framebox} commands are like @code{\mbox},
except that they put a frame around the outside of the box being created.

In addition, the @code{\framebox} command allows for explicit
specification of the box width with the optional @var{width} argument
(a dimension), and positioning with the optional @var{position}
argument. @c xxref

@findex \fboxrule
@findex \fboxsep
Both commands produce a rule of thickness @code{\fboxrule} (default
@samp{.4pt}), and leave a space of @code{\fboxsep} (default
@samp{3pt}) between the rule and the contents of the box.

@xref{\framebox (picture)}, for the @code{\framebox} command in the
@code{picture} environment.


@node lrbox
@section @code{lrbox}
@findex lrbox

@code{\begin@{lrbox@}@{cmd@} text \end@{lrbox@}}

This is the environment form of @code{\sbox}.

The text inside the environment is saved in the box @code{cmd}, which
must have been declared with @code{\newsavebox}.


@node \makebox
@section @code{\makebox}
@findex \makebox

Synopsis:

@example
\makebox[@var{width}][@var{position}]@{@var{text}@}
@end example

The @code{\makebox} command creates a box just wide enough to contain
the @var{text} specified.  The width of the box is specified by the
optional @var{width} argument.  The position of the text within the box
is determined by the optional @var{position} argument, which may take
the following values:

@table @code
@item c
Centered (default).
@item l
Flush left.
@item r
Flush right.
@item s
Stretch (justify) across entire @var{width}; @var{text} must contain
stretchable space for this to work.
@end table

@code{\makebox} is also used within the picture environment
@pxref{\makebox (picture)}.


@node \parbox
@section @code{\parbox}
@findex \parbox

Synopsis:

@example
\parbox[@var{position}][@var{height}][@var{inner-pos}]@{@var{width}@}@{@var{text}@}
@end example

The @code{\parbox} command produces a box whose contents are created
in @code{paragraph} mode.  It should be used to make a box small
pieces of text, with nothing fancy inside.  In particular, you
shouldn't use any paragraph-making environments inside a
@code{\parbox} argument.  For larger pieces of text, including ones
containing a paragraph-making environment, you should use a
@code{minipage} environment (@pxref{minipage}).

@code{\parbox} has two mandatory arguments:

@table @var
@item width
the width of the parbox;
@item text
the text that goes inside the parbox.
@end table

The optional @var{position} argument allows you to align either the
top or bottom line in the parbox with the baseline of the surrounding
text (default is top).

The optional @var{height} argument overrides the natural height of the box.

The @var{inner-pos} argument controls the placement of the text inside
the box, as follows; if it is not specified, @var{position} is used.

@table @code
@item t
text is placed at the top of the box.
@item c
text is centered in the box.
@item b
text is placed at the bottom of the box.
@item s
stretch vertically; the text must contain vertically stretchable space
for this to work.
@end table


@node \raisebox
@section @code{\raisebox}
@findex \raisebox

Synopsis:

@example
\raisebox@{distance@}[@var{height}][@var{depth}]@{text@}
@end example

The @code{\raisebox} command raises or lowers @var{text}.  The first
mandatory argument specifies how high @var{text} is to be raised (or
lowered if it is a negative amount).  @var{text} itself is processed
in LR mode.

The optional arguments @var{height} and @var{depth} are dimensions.
If they are specified, @LaTeX{} treats @var{text} as extending a
certain distance above the baseline (height) or below (depth),
ignoring its natural height and depth.


@node \savebox
@section @code{\savebox}
@findex \savebox

Synopsis:

@example
\savebox@{@var{\boxcmd}@}[@var{width}][@var{pos}]@{@var{text}@}
@end example

This command typeset @var{text} in a box just as with @code{\makebox}
(@pxref{\makebox}), except that instead of printing the resulting box,
it saves it in the box labeled @var{\boxcmd}, which must have been
declared with @code{\newsavebox} (@pxref{\newsavebox}).


@node \sbox
@section @code{\sbox@{@var{\boxcmd}@}@{@var{text}@}}
@findex \sbox

Synopsis:

@example
\sbox@{@var{\boxcmd}@}@{@var{text}@}
@end example

@code{\sbox} types @var{text} in a box just as with @code{\mbox}
(@pxref{\mbox}) except that instead of the resulting box being
included in the normal output, it is saved in the box labeled
@var{\boxcmd}.  @var{\boxcmd} must have been previously declared with
@code{\newsavebox} (@pxref{\newsavebox}).


@node \usebox
@section @code{\usebox@{@var{\boxcmd}@}}
@findex \usebox

Synopsis:

@example
\usebox@{@var{\boxcmd}@}
@end example

@code{\usebox} produces the box most recently saved in the bin
@var{\boxcmd} by a @code{\savebox} command (@pxref{\savebox}).


@node Special insertions
@chapter Special insertions

@LaTeX{} provides commands for inserting characters that have a
special meaning do not correspond to simple characters you can type.

@menu
* Reserved characters::     Inserting @samp{# $ % & ~ _ ^ \ @{ @}}
* Text symbols::            Inserting other non-letter symbols in text.
* Accents::                 Inserting accents.
* Non-English characters::  Inserting other non-English characters.
* \rule::                   Inserting lines and rectangles.
* \today::                  Inserting today's date.
@end menu


@node Reserved characters
@section Reserved characters
@cindex reserved characters
@cindex characters, reserved

The following characters play a special role in @LaTeX{} and are called
``reserved characters'' or ``special characters''.

@example
# $ % & ~ _ ^ \ @{ @}
@end example

@findex \#
@findex \$
@findex \%
@findex \&
@findex \_
@findex \@{
@findex \@}
Whenever you write one of these characters into your file, @LaTeX{}
will do something special.  If you simply want the character to be
printed as itself, include a @code{\} in front of the character.  For
example, @code{\$} will produce @code{$} in your output.

@findex \backslash
One exception to this rule is @code{\} itself, because @code{\\} has
its own special (context-dependent) meaning.  A roman \ is produced by
typing @code{$\backslash$} in your file, and a typewriter @code{\} is
produced by using @samp{\} in a verbatim command (@pxref{verbatim}).

@findex \~
@findex \^
Also, @code{\~} and @code{\^} place tilde and circumflex accents over
the following letter, as in @~{o} and @^{o} (@pxref{Accents}); to get
a standalone @code{~} or @code{^}, you can again use a verbatim
command.

@findex \symbol
@cindex accessing any character of a font

Finally, you can access any character of the current font once you
know its number by using the @code{\symbol} command. For example, the
visible space character used in the @code{\verb*} command has the code
decimal 32, so it can be typed as @code{\symbol@{32@}}.

You can also specify octal numbers with @code{'} or hexadecimal numbers
with @code{"}, so the previous example could also be written as
@code{\symbol@{'40@}} or @code{\symbol@{"20@}}.


@node Text symbols
@section Text symbols

@cindex text symbols
@findex textcomp @r{package}
@LaTeX{} provides commands to generate a number of non-letter symbols
in running text.  Some of these, especially the more obscure ones, are
not available in OT1; you may need to load the @code{textcomp} package.

@ftable @code

@item \copyright
@itemx \textcopyright
@cindex copyright symbol
The copyright symbol, @copyright{}.

@item \dag
@cindex dagger, in text
The dagger symbol (in text).

@item \ddag
@cindex double dagger, in text
The double dagger symbol (in text).

@item \LaTeX
@cindex @LaTeX{} logo
@cindex logo, @LaTeX{}
The @LaTeX{} logo.

@item \LaTeXe
@cindex @LaTeX{}2e logo
@cindex logo, @LaTeX{}2e
The @LaTeX{}2e logo.

@item \guillemotleft @r{(@guillemotleft{})}
@itemx \guillemotright @r{(@guillemotright{})}
@itemx \guilsinglleft @r{(@guilsinglleft{})}
@itemx \guilsinglright @r{(@guilsinglright{})}
@cindex double guillemets
@cindex single guillemets
@cindex left angle quotation marks
@cindex right angle quotation marks
@cindex double angle quotation marks
@cindex single angle quotation marks
@cindex French quotation marks
@cindex quotation marks, French
Double and single angle quotation marks, commonly used in French:
@guillemotleft{}, @guillemotright{}, @guilsinglleft{}, @guilsinglright{}.

@item \ldots
@itemx \dots
@itemx \textellipsis
@cindex ellipsis
An ellipsis (three dots at the baseline): `@dots{}'.  @code{\ldots}
and @code{\dots} also work in math mode.

@item \lq
@cindex left quote
@cindex opening quote
Left (opening) quote: `.

@item \P
@itemx \textparagraph
@cindex paragraph symbol
@cindex pilcrow
Paragraph sign (pilcrow).

@item \pounds
@itemx \textsterling
@cindex pounds symbol
@cindex sterling symbol
English pounds sterling: @pounds{}.

@item \quotedblbase @r{(@quotedblbase{})}
@itemx \quotesinglbase @r{(@quotesinglbase{})}
@cindex double low-9 quotation mark
@cindex single low-9 quotation mark
@cindex low-9 quotation marks, single and double
Double and single quotation marks on the baseline:
@quotedblbase{} and @quotesinglbase{}.

@item \rq
@cindex right quote
@cindex closing quote
Right (closing) quote: '.

@item \S
@cindex section symbol
Section symbol.

@item \TeX
@cindex @TeX{} logo
@cindex logo, @TeX{}
The @TeX{} logo.

@item \textasciicircum
@cindex circumflex, ASCII, in text
@cindex ASCII circumflex, in text
ASCII circumflex: ^.

@item \textasciitilde
@cindex tilde, ASCII, in text
@cindex ASCII tilde, in text
ASCII tilde: ~.

@item \textasteriskcentered
@cindex asterisk, centered, in text
@cindex centered asterisk, in text
Centered asterisk: *.

@item \textbackslash
@cindex backslash, in text
Backslash: \.

@item \textbar
@cindex vertical bar, in text
@cindex bar, vertical, in text
Vertical bar: |.

@item \textbardbl
@cindex vertical bar, double, in text
@cindex bar, double vertical, in text
@cindex double vertical bar, in text
Double vertical bar.

@item \textbigcircle
@cindex big circle symbols, in text
@cindex circle symbol, big, in text
Big circle symbol.

@item \textbraceleft
@cindex left brace, in text
@cindex brace, left, in text
Left brace: @{.

@item \textbraceright
@cindex right brace, in text
@cindex brace, right, in text
Right brace: @}.

@item \textbullet
@cindex bullet, in text
Bullet: @bullet{}.

@item \textcircled@{@var{letter}@}
@cindex circled letter, in text
@var{letter} in a circle, as in @registeredsymbol{}.

@item \textcompwordmark
@itemx \textcapitalwordmark
@itemx \textascenderwordmark
@cindex composite word mark, in text
@cindex cap height
@cindex ascender height
Composite word mark (invisible).  The @code{\textcapital...} form
has the cap height of the font, while the @code{\textascender...} form
has the ascender height.

@item \textdagger
@cindex dagger, in text
Dagger: @math{\dag}.

@item \textdaggerdbl
@cindex dagger, double, in text
@cindex double dagger, in text
Double dagger: @math{\ddag}.

@item \textdollar @r{(or @code{$})}
@cindex dollar sign
@cindex currency, dollar
Dollar sign: $.

@item \textemdash @r{(or @code{---})}
@cindex em-dash
Em-dash: --- (for punctuation).

@item \textendash @r{(or @code{--})}
@cindex e-dash
En-dash: --- (for ranges).

@item \texteuro
@cindex euro symbol
@cindex currency, euro
The Euro symbol: @euro{}.

@item \textexclamdown @r{(or @code{!`})}
@cindex exclamation point, upside-down
Upside down exclamation point: @exclamdown{}.

@item \textgreater
@cindex greater than symbol, in text
Greater than: >.

@item \textless
@cindex less than symbol, in text
Less than: <.

@item \textleftarrow
@cindex arrow, left, in text
@cindex left arrow, in text
Left arrow.

@item \textordfeminine
@itemx \textordmasculine
@cindex feminine ordinal symbol
@cindex masculine ordinal symbol
@cindex ordinals, feminine and masculine
@cindex Spanish ordinals, feminine and masculine
Feminine and masculine ordinal symbols: @ordf{}, @ordm{}.

@item \textperiodcentered
@cindex period, centered, in text
@cindex centered period, in text
Centered period: @math{\cdot}.

@item \textquestiondown @r{(or @code{?`})}
@cindex question mark, upside-down
Upside down question mark: @questiondown{}.

@item \textquotedblleft @r{(or @code{``})}
@cindex left quote, double
@cindex double left quote
Double left quote: ``.

@item \textquotedblright @r{(or @code{'})}
@cindex right quote, double
@cindex double right quote
Double right quote: ''.

@item \textquoteleft @r{(or @code{`})}
@cindex left quote, single
@cindex single left quote
Single left quote: `.

@item \textquoteright @r{(or @code{'})}
@cindex right quote, single
@cindex single right quote
Single right quote: '.

@item \textquotestraightbase
@itemx \textquotestraightdblbase
@cindex quote, straight base
@cindex straight quote, base
@cindex double quote, straight base
@cindex straight double quote, base
Single and double straight quotes on the baseline.

@item \textregistered
@cindex registered symbol
Registered symbol: @registeredsymbol{}.

@item \textrightarrow
@cindex arrow, right, in text
@cindex right arrow, in text
Right arrow.

@item \textthreequartersemdash
@cindex three-quarters em-dash
@cindex em-dash, three-quarters
``Three-quarters'' em-dash, between en-dash and em-dash.

@item \texttrademark
@cindex trademark symbol
Trademark symbol: @math{^{\hbox{TM}}}.

@item \texttwelveudash
@cindex two-thirds em-dash
@cindex em-dash, two-thirds
``Two-thirds'' em-dash, between en-dash and em-dash.

@item \textunderscore
@cindex underscore, in text
Underscore: _.

@item \textvisiblespace
@cindex visible space symbol, in text
Visible space symbol.

@end ftable


@node Accents
@section Accents

@cindex accents
@cindex characters, accented
@cindex letters, accented

@cindex @code{babel} package
@cindex multilingual support
@LaTeX{} has wide support for many of the world's scripts and
languages, through the @code{babel} package and related support.  This
section does not attempt to cover all that support.  It merely lists
the core @LaTeX{} commands for creating accented characters.

The @code{\capital...} commands produce alternative forms for use with
capital letters.  These are not available with OT1.

@table @code
@item \"
@itemx \capitaldieresis
@findex \" @r{(umlaut accent)}
@findex \capitaldieresis
@cindex umlaut accent
@cindex dieresis accent
Produces an umlaut (dieresis), as in @"{o}.

@item \'
@itemx \capitalacute
@findex \' @r{(acute accent)}
@findex \capitalacute
@cindex acute accent
Produces an acute accent, as in @'{o}.  In the @code{tabbing}
environment, pushes current column to the right of the previous column
(@pxref{tabbing}).

@item \.
@findex \. @r{(dot-over accent)}
@cindex dot accent
@cindex dot-over accent
Produces a dot accent over the following, as in @dotaccent{o}.

@item \=
@itemx \capitalmacron
@findex \= @r{(macron accent)}
@findex \capitalmacron
@cindex macron accent
@cindex overbar accent
@cindex bar-over accent
Produces a macron (overbar) accent over the following, as in @={o}.

@item \^
@itemx \capitalcircumflex
@findex \^ @r{(circumflex accent)}
@findex \capitalcircumflex
@cindex circumflex accent
@cindex hat accent
Produces a circumflex (hat) accent over the following, as in @^{o}.

@item \`
@itemx \capitalgrave
@findex \` @r{(grave accent)}
@findex \capitalgrave
@cindex grave accent
Produces a grave accent over the following, as in @`{o}.  In the
@code{tabbing} environment, move following text to the right margin
(@pxref{tabbing}).

@item \~
@itemx \capitaltilde
@findex \~ @r{(tilde accent)}
@findex \capitaltilde
@cindex tilde accent
Produces a tilde accent over the following, as in @~{n}.

@item \b
@findex \b @r{(bar-under accent)}
@cindex bar-under accent
Produces a bar accent under the following, as in @ubaraccent{o}.

@item \c
@itemx \capitalcedilla
@findex \c @r{(cedilla accent)}
@findex \capitalcedilla
@cindex cedilla accent
Produces a cedilla accent under the following, as in @,{c}.

@item \d
@itemx \capitaldotaccent
@findex \d @r{(dot-under accent)}
@findex \capitaldotaccent
@cindex dot-under accent
Produces a dot accent under the following, as in @udotaccent{o}.

@item \H
@itemx \capitalhungarumlaut
@findex \H @r{(Hungarian umlaut accent)}
@findex \capitalhungarumlaut
@cindex hungarian umlaut accent
Produces a long Hungarian umlaut accent over the following, as in @H{o}.

@item \i
@findex \i @r{(dotless i)}
@cindex dotless i
Produces a dotless i, as in `@dotless{i}'.

@item \j
@findex \j @r{(dotless j)}
@cindex dotless j
Produces a dotless j, as in `@dotless{j}'.

@item \k
@itemx \capitalogonek
@findex \k @r{(ogonek)}
@findex \capitalogonek
@cindex ogonek
Produces a letter with ogonek, as in `@ogonek{o}'.  Not available in
the OT1 encoding.

@item \r
@itemx \capitalring
@findex \r @r{(ring accent)}
@findex \capitalring
@cindex ring accent
Produces a ring accent, as in `@ringaccent{o}'.

@item \t
@itemx \capitaltie
@itemx \newtie
@itemx \capitalnewtie
@findex \t @r{(tie-after accent)}
@findex \capitaltie
@findex \newtie
@findex \capitalnewtie
@cindex tie-after accent
Produces a tie-after accent, as in `@tieaccent{oo}'.  The
@code{\newtie} form is centered in its box.

@item \u
@itemx \capitalbreve
@findex \u @r{(breve accent)}
@findex \capitalbreve
@cindex breve accent
Produces a breve accent, as in `@u{o}'.

@item \underbar
@findex \underbar
@cindex underbar
Not exactly an accent, this produces a bar under the argument text.
The argument is always processed in horizontal mode.  The bar is
always a fixed position under the baseline, thus crossing through
descenders.  See also @code{\underline} in @ref{Math miscellany}.

@item \v
@itemx \capitalcaron
@findex \v @r{(breve accent)}
@findex \capitalcaron
@cindex hacek accent
@cindex check accent
@cindex caron accent
Produces a h@'a@v{c}ek (check, caron) accent, as in `@v{o}'.

@end table


@node Non-English characters
@section Non-English characters

@cindex special characters
@cindex non-English characters
@cindex characters, non-English
@cindex letters, non-English

Here are the basic @LaTeX{} commands for inserting characters commonly
used in languages other than English.

@table @code

@item \aa
@itemx \AA
@findex \aa (@aa{})
@findex \AA (@AA{})
@cindex aring
@aa{} and @AA{}.

@item \ae
@itemx \AE
@findex \ae (@ae{})
@findex \AE (@AE{})
@cindex ae ligature
@ae{} and @AE{}.

@item \dh
@itemx \DH
@findex \dh (@dh{})
@findex \DH (@DH{})
@cindex Icelandic eth
@cindex eth, Icelandic letter
Icelandic letter eth: @dh{} and @DH{}.

@item \dj
@itemx \DJ
@findex \dj
@findex \DJ
Crossed d and D, a.k.a.@: capital and small letter d with stroke.

@item \ij
@itemx \IJ
@findex \ij (ij)
@findex \IJ (IJ)
@cindex ij letter, Dutch
ij and IJ (except somewhat closer together than appears here).

@item \l
@itemx \L
@findex \l (@l{})
@findex \L (@L{})
@cindex polish l
@l{} and @L{}.

@item \ng
@itemx \NG
@findex \ng
@findex \NG
Latin letter eng, also used in phonetics.

@item \o
@itemx \O
@findex \o (@o{})
@findex \O (@O{})
@cindex oslash
@o{} and @O{}.

@item \oe
@itemx \OE
@findex \oe (@oe{})
@findex \OE (@OE{})
@cindex oe ligature
@oe{} and @OE{}.

@item \ss
@itemx \SS
@findex \ss (@ss{})
@findex \SS (SS)
@cindex es-zet German letter
@cindex sharp S letters
@ss{} and SS.

@item \th
@itemx \TH
@findex \th (@th{})
@findex \TH (@TH{})
@cindex Icelandic thorn
@cindex thorn, Icelandic letter
Icelandic letter thorn: @th{} and @TH{}.

@end table


@node \rule
@section @code{\rule}
@findex \rule

Synopsis:

@example
\rule[@var{raise}]@{@var{width}@}@{@var{thickness}@}
@end example

The @code{\rule} command produces @dfn{rules}, that is, lines or
rectangles.  The arguments are:

@table @var
@item raise
How high to raise the rule (optional).

@item width
The length of the rule (mandatory).

@item thickness
The thickness of the rule (mandatory).
@end table


@node \today
@section @code{\today}
@findex \today

The @code{\today} command produces today's date, in the format
@samp{@var{month} @var{dd}, @var{yyyy}}; for example, `July 4, 1976'.
It uses the predefined counters @code{\day}, @code{\month}, and
@code{\year} (@pxref{\day \month \year}) to do this.  It is not
updated as the program runs.

@cindex @code{datetime} package
The @code{datetime} package, among others, can produce a wide variety
of other date formats.


@node Splitting the input
@chapter Splitting the input
@cindex splitting the input file
@cindex input file

A large document requires a lot of input.  Rather than putting the whole
input in a single large file, it's more efficient to split it into
several smaller ones.  Regardless of how many separate files you use,
there is one that is the root file; it is the one whose name you type
when you run @LaTeX{}.

@xref{filecontents}, for an environment that allows bundling an
external file to be created with the main document.

@menu
* \include::            Conditionally include a file.
* \includeonly::        Determine which files are included.
* \input::              Unconditionally include a file.
@end menu


@node \include
@section @code{\include}
@findex \include

Synopsis:

@example
\include@{@var{file}@}
@end example

If no @code{\includeonly} command is present, the @code{\include}
command executes @code{\clearpage} to start a new page
(@pxref{\clearpage}), then reads @var{file}, then does another
@code{\clearpage}.

Given an @code{\includeonly} command, the @code{\include} actions are
only run if @var{file} is listed as an argument to
@code{\includeonly}.  See the next section.

@cindex nested @code{\include}, not allowed
The @code{\include} command may not appear in the preamble or in a file
read by another @code{\include} command.


@node \includeonly
@section \@code{includeonly}
@findex \includeonly

Synopsis:

@example
\includeonly@{@var{file1},@var{file2},...@}
@end example

The @code{\includeonly} command controls which files will be read by
subsequent @code{\include} commands.  The list of filenames is
comma-separated. Each @var{file} must exactly match a filename
specified in a @code{\include} command for the selection to be
effective.

This command can only appear in the preamble.


@node \input
@section \input
@findex \input

Synopsis:

@example
\input@{@var{file}@}
@end example

The @code{\input} command causes the specified @var{file} to be read
and processed, as if its contents had been inserted in the current
file at that point.

If @var{file} does not end in @samp{.tex} (e.g., @samp{foo} or
@samp{foo.bar}), it is first tried with that extension (@samp{foo.tex}
or @samp{foo.bar.tex}).  If that is not found, the original @var{file}
is tried (@samp{foo} or @samp{foo.bar}).

@node Front/back matter
@chapter Front/back matter

@menu
* Tables of contents::
* Glossaries::
* Indexes::
@end menu


@node Tables of contents
@section Tables of contents

@cindex table of contents, creating

@findex \tableofcontents
@findex .toc @r{file}
A table of contents is produced with the @code{\tableofcontents}
command.  You put the command right where you want the table of
contents to go; @LaTeX{} does the rest for you.  A previous run must
have generated a @file{.toc} file.

The @code{\tableofcontents} command produces a heading, but it does
not automatically start a new page.  If you want a new page after the
table of contents, write a @code{\newpage} command after the
@code{\tableofcontents} command.

@findex \listoffigures
@findex \listoftables
@findex .lof @r{file}
@findex .lot @r{file}
The analogous commands @code{\listoffigures} and @code{\listoftables}
produce a list of figures and a list of tables (from @file{.lof} and
@file{.lot} files), respectively.  Everything works exactly the same
as for the table of contents.

@findex \nofiles
The command @code{\nofiles} overrides these commands, and
@emph{prevents} any of these lists from being generated.

@menu
* \addcontentsline::    Add an entry to table of contents, etc.
* \addtocontents::      Add text directly to table of contents file, etc.
@end menu


@node \addcontentsline
@subsection \addcontentsline
@findex \addcontentsline@{@var{ext}@}@{@var{unit}@}@{@var{text}@}
@cindex table of contents entry, manually adding

The @code{\addcontentsline}@{@var{ext}@}@{@var{unit}@}@{@var{text}@}
command adds an entry to the specified list or table where:

@table @var
@item ext
The extension of the file on which information is to be written,
typically one of: @code{toc} (table of contents), @code{lof} (list of
figures), or @code{lot} (list of tables).

@item unit
The name of the sectional unit being added, typically one of the
following, matching the value of the @var{ext} argument:

@table @code
@item toc
The name of the sectional unit: @code{part}, @code{chapter},
@code{section}, @code{subsection}, @code{subsubsection}.
@item lof
For the list of figures.
@item lot
For the list of tables.
@end table

@item entry
The text of the entry.
@end table

@findex \contentsline
What is written to the @file{.@var{ext}} file is the
command @code{\contentsline@{@var{unit}@}@{@var{name}@}}.

@c xx how hardwired are these values?  other unit names?


@node \addtocontents
@subsection \addtocontents
@findex \addtocontents@{@var{ext}@}@{@var{text}@}

The @code{\addtocontents}@{@var{ext}@}@{@var{text}@} command adds text
(or formatting commands) directly to the @file{.@var{ext}} file that
generates the table of contents or lists of figures or tables.

@table @var
@item ext
The extension of the file on which information is to be written,
typically one of: @file{toc} (table of contents), @file{lof} (list of
figures), or @file{lot} (list of tables).

@item text
The text to be written.
@end table


@node Glossaries
@section Glossaries
@cindex glossaries

@findex \makeglossary
The command @code{\makeglossary} enables creating glossaries.

@findex \glossary
@cindex @file{.glo} file
The command @code{\glossary@{@var{text}@}} writes a glossary entry for
@var{text} to an auxiliary file with the @file{.glo} extension.

@findex \glossaryentry
Specifically, what gets written is the command
@code{\glossaryentry@{@var{text}@}@{@var{pageno}@}}, where
@var{pageno} is the current @code{\thepage} value.

@cindex glossary @r{package}
The @code{glossary} package on CTAN provides support for fancier
glossaries.


@node Indexes
@section Indexes
@cindex indexes

@findex \makeindex
The command @code{\makeindex} enables creating indexes.  Put this in
the preamble.

@findex \index
@cindex @file{.idx} file
The command @code{\index@{@var{text}@}} writes an index entry for
@var{text} to an auxiliary file with the @file{.idx} extension.

@findex \indexentry
Specifically, what gets written is the command
@code{\indexentry@{@var{text}@}@{@var{pageno}@}}, where @var{pageno}
is the current @code{\thepage} value.

@cindex `see' and `see also' index entries
@cindex  index entries, `see' and `see also'
To generate a index entry for `bar' that says `See foo', use a
vertical bar: @code{\index@{bar|see@{foo@}@}}.  Use @code{seealso}
instead of @code{see} to make a `See also' entry.

@findex \seename
@findex \alsoname
The text `See' is defined by the macro @code{\seename}, and `See also'
by the macro @code{\alsoname}.  These can be redefined for other
languages.

@cindex @command{makeindex} program
@cindex @command{xindy} program
@cindex @file{.ind} file
The generated @file{.idx} file is then sorted with an external
command, usually either @command{makeindex}
(@url{http://mirror.ctan.org/indexing/makeindex}) or (the
multi-lingual) @command{xindy} (@url{http://xindy.sourceforge.net}).
This results in a @file{.ind} file, which can then be read to typeset
the index.

@findex printindex
@cindex @code{makeidx} package
The index is usually generated with the @code{\printindex} command.
This is defined in the @code{makeidx} package, so
@code{\usepackage@{makeidx@}} needs to be in the preamble.

@findex indexspace
The rubber length @code{\indexspace} is inserted before each new
letter in the printed index; its default value is @samp{10pt plus5pt
minus3pt}.

@cindex @code{showidx} package
The @code{showidx} package causes each index entries to be shown in
the margin on the page where the entry appears.  This can help in
preparing the index.

@cindex @code{multind} package
The @code{multind} package supports multiple indexes.  See also the
@TeX{} FAQ entry on this topic,
@url{http://www.tex.ac.uk/cgi-bin/texfaq2html?label=multind}.


@node Letters
@chapter Letters
@cindex letters
@cindex creating letters

You can use @LaTeX{} to typeset letters, both personal and business.  The
@code{letter} document class is designed to make a number of letters at
once, although you can make just one if you so desire.

Your @file{.tex} source file has the same minimum commands as the other
document classes, i.e., you must have the following commands as a
minimum:

@example
 \documentclass@{letter@}
 \begin@{document@}
  ... letters ...
 \end@{document@}
@end example

Each letter is a @code{letter} environment, whose argument is the name
and address of the recipient.  For example, you might have:

@example
 \begin@{letter@}@{Mr. Joe Smith\\ 2345 Princess St.
      \\ Edinburgh, EH1 1AA@}
   ...
 \end@{letter@}
@end example

The letter itself begins with the @code{\opening} command.  The text of
the letter follows.  It is typed as ordinary @LaTeX{} input.  Commands that
make no sense in a letter, like @code{\chapter}, do not work.  The letter
closes with a @code{\closing} command.

@findex \\ @r{for letters}
After the @code{closing}, you can have additional material.  The
@code{\cc} command produces the usual ``cc: @dots{}''.  There's also a
similar @code{\encl} command for a list of enclosures. With both these
commands, use @code{\\} to separate the items.

These commands are used with the @code{letter} class.

@menu
* \address::            Your return address.
* \cc::                 Cc list.
* \closing::            Saying goodbye.
* \encl::               List of enclosed material.
* \location::           Your organization's address.
* \makelabels::         Making address labels.
* \name::               Your name, for the return address.
* \opening::            Saying hello.
* \ps::                 Adding a postscript.
* \signature::          Your signature.
* \startbreaks::        Allow page breaks.
* \stopbreaks::         Disallow page breaks.
* \telephone::          Your phone number.
@end menu


@node \address
@section \address@{@var{return-address@}}
@findex \address

The @code{\address} specifies the return address of a letter, as it
should appear on the letter and the envelope.  Separate lines of the
address should be separated by @code{\\} commands.

If you do not make an @code{\address} declaration, then the letter
will be formatted for copying onto your organization's standard
letterhead.  (@xref{Overview}, for details on your local
implementation).  If you give an @code{\address} declaration, then the
letter will be formatted as a personal letter.


@node \cc
@section @code{\cc}

@findex \cc
@cindex cc list, in letters

Synopsis:

@example
\cc@{@var{name1}\\@var{name2}@}
@end example

Produce a list of @var{name}s the letter was copied to.  Each name is
printed on a separate line.


@node \closing
@section @code{\closing}

@findex \closing
@cindex letters, ending
@cindex closing letters

Synopsis:

@example
\closing@{text@}
@end example

A letter closes with a @code{\closing} command, for example,
@example
\closing@{Best Regards,@}
@end example


@node \encl
@section @code{\encl}

@findex \encl
@cindex enclosure list

Synopsis:

@example
\encl@{@var{line1}\\@var{line2}@}
@end example

Declare a list of one more enclosures.


@node \location
@section @code{\location}
@findex \location

@code{\location@{address@}}

This modifies your organization's standard address.  This only appears
if the @code{firstpage} pagestyle is selected.


@node \makelabels
@section @code{\makelabels}
@findex \makelabels

@code{\makelabels@{number@}}

If you issue this command in the preamble, @LaTeX{} will create a sheet of
address labels. This sheet will be output before the letters.



@node \name
@section @code{\name}
@findex \name

@code{\name@{June Davenport@}}

Your name, used for printing on the envelope together with the return
address.


@node \opening
@section @code{\opening@{@var{text}@}}
@findex \opening
@cindex letters, starting

Synopsis:

@example
\opening@{@var{text}@}
@end example

A letter begins with the @code{\opening} command.  The mandatory
argument, @var{text}, is whatever text you wish to start your letter.
For instance:

@example
\opening@{Dear Joe,@}
@end example


@node \ps
@section @code{\ps}
@findex \ps
@cindex postscript, in letters

Use the @code{\ps} command to start a postscript in a letter, after
@code{\closing}.


@node \signature
@section @code{\signature@{@var{text}@}}
@findex \signature

Your name, as it should appear at the end of the letter underneath the
space for your signature.  @code{\\} starts a new line within
@var{text} as usual.


@node \startbreaks
@section @code{\startbreaks}
@findex \startbreaks

@code{\startbreaks}

Used after a @code{\stopbreaks} command to allow page breaks again.


@node \stopbreaks
@section @code{\stopbreaks}
@findex \stopbreaks

@code{\stopbreaks}

Inhibit page breaks until a @code{\startbreaks} command occurs.


@node \telephone
@section @code{\telephone}
@findex \telephone

@code{\telephone@{number@}}

This is your telephone number.  This only appears if the
@code{firstpage} pagestyle is selected.


@node Terminal input/output
@chapter Terminal input/output
@cindex input/output
@cindex terminal input/output

@menu
* \typein::             Read text from the terminal.
* \typeout::            Write text to the terminal.
@end menu


@node \typein
@section @code{\typein[@var{cmd}]@{@var{msg}@}}
@findex \typein

Synopsis:

@example
\typein[@var{\cmd}]@{@var{msg}@}
@end example

@code{\typein} prints @var{msg} on the terminal and causes @LaTeX{} to
stop and wait for you to type a line of input, ending with return.  If
the optional @var{\cmd} argument is omitted, the typed input is
processed as if it had been included in the input file in place of the
@code{\typein} command.  If the @var{\cmd} argument is present, it
must be a command name.  This command name is then defined or
redefined to be the typed input.


@node \typeout
@section @code{\typeout@{@var{msg}@}}
@findex \typeout

Synopsis:

@example
\typeout@{@var{msg}@}
@end example

Prints @code{msg} on the terminal and in the @code{log} file.
Commands in @code{msg} that are defined with @code{\newcommand} or
@code{\renewcommand} (among others) are replaced by their definitions
before being printed.

@LaTeX{}'s usual rules for treating multiple spaces as a single space
and ignoring spaces after a command name apply to @code{msg}.  A
@code{\space} command in @code{msg} causes a single space to be
printed, independent of surrounding spaces.  A @code{^^J} in
@code{msg} prints a newline.


@node Command line
@chapter Command line
@cindex command line

@findex .tex, @r{default extension}
The input file specification indicates the file to be formatted;
@TeX{} uses @file{.tex} as a default file extension.  If you omit the
input file entirely, @TeX{} accepts input from the terminal.  You can
also specify arbitrary @LaTeX{} input by starting with a backslash.
For example, this processes @file{foo.tex} without pausing after every
error:

@example
latex '\nonstopmode\input foo.tex'
@end example

@findex --help @r{command-line option}
With many, but not all, implementations, command-line options can also
be specified in the usual Unix way, starting with @samp{-} or
@samp{--}.  For a list of those options, try @samp{latex --help}.

@cindex @samp{*} prompt
@cindex prompt, @samp{*}
@findex \stop
If @LaTeX{} stops in the middle of the document and gives you a
@samp{*} prompt, it is waiting for input.  You can type @code{\stop}
(and return) and it will prematurely end the document.

@xref{@TeX{} engines}, for other system commands invoking @LaTeX{}.


@node Document templates
@appendix Document templates
@cindex document templates

Although not reference material, perhaps these document templates will
be useful.  Additional template resources are listed at
@url{http://tug.org/interest.html#latextemplates}.

@menu
* beamer template::
* book template::
* tugboat template::
@end menu


@node beamer template
@section @code{beamer} template

@cindex @code{beamer} template and class
The @code{beamer} class creates presentation slides.  It has a vast
array of features, but here is a basic template:

@verbatim
\documentclass{beamer}

\title{Beamer Class template}
\author{Alex Author}
\date{July 31, 2007}

\begin{document}

\maketitle

% without [fragile], any {verbatim} code gets mysterious errors.
\begin{frame}[fragile]
 \frametitle{First Slide}

\begin{verbatim}
  This is \verbatim!
\end{verbatim}

\end{frame}

\end{document}
@end verbatim

One web resource for this:
@url{http://robjhyndman.com/hyndsight/beamer/}.


@node book template
@section @code{book} template

@verbatim
\documentclass{book}
\title{Book Class Template}
\author{Alex Author}

\begin{document}
\maketitle

\chapter{First}
Some text.

\chapter{Second}
Some other text.

\section{A subtopic}
The end.
\end{document}
@end verbatim


@node tugboat template
@section @code{tugboat} template

@cindex TUGboat template
@cindex @code{ltugboat} class

@cite{TUGboat} is the journal of the @TeX{} Users Group,
@url{http://tug.org/TUGboat}.

@verbatim
\documentclass{ltugboat}
\usepackage{graphicx}
\usepackage{ifpdf}
\ifpdf
\usepackage[breaklinks,hidelinks]{hyperref}
\else
\usepackage{url}
\fi

\title{Example \TUB\ article}

% repeat info for each author.
\author{First Last}
\address{Street Address \\ Town, Postal \\ Country}
\netaddress{user (at) example dot org}
\personalURL{http://example.org/~user/}

\begin{document}

\maketitle

\begin{abstract}
This is an example article for \TUB{}.
\end{abstract}

\section{Introduction}

This is an example article for \TUB, from
\url{http://tug.org/TUGboat/location.html}.

We recommend the \texttt{graphicx} package for image inclusions, and the
\texttt{hyperref} package for active urls in the \acro{PDF} output.
Nowadays \TUB\ is produced using \acro{PDF} files exclusively.

The \texttt{ltugboat} class provides these abbreviations and many more:

% verbatim blocks are often better in \small
\begin{verbatim}[\small]
\AllTeX \AMS \AmS \AmSLaTeX \AmSTeX \aw \AW
\BibTeX \CTAN \DTD \HTML
\ISBN \ISSN \LaTeXe
\Mc \mf \MFB \mtex \PCTeX \pcTeX
\PiC \PiCTeX \plain \POBox \PS
\SC \SGML \SliTeX \TANGLE \TB \TP
\TUB \TUG \tug
\UG \UNIX \VAX \XeT \WEB \WEAVE

\Dash \dash \vellipsis \bull \cents \Dag
\careof \thinskip

\acro{FRED} -> {\small[er] fred}  % please use!
\cs{fred}   -> \fred
\env{fred}  -> \begin{fred}
\meta{fred} -> <fred>
\nth{n}     -> 1st, 2nd, ...
\sfrac{3/4} -> 3/4
\booktitle{Book of Fred}
\end{verbatim}

For more information, see the ltubguid document at:
\url{http://mirror.ctan.org/macros/latex/contrib/tugboat}
(we recommend using \verb|mirror.ctan.org| for \CTAN\ references).

Email \verb|tugboat@tug.org| if problems or questions.

\bibliographystyle{plain}  % we recommend the plain bibliography style
\nocite{book-minimal}      % just making the bibliography non-empty
\bibliography{xampl}       % xampl.bib comes with BibTeX

\makesignature
\end{document}
@end verbatim


@node Concept Index
@unnumbered Concept Index

@printindex cp

@c The name of the `Command Index' node must NOT be altered for ltx-help.el.
@node Command Index
@unnumbered Command Index

@printindex fn

@bye

\def\DeclareTextCommand{\foo}{T1}
%    then |\foo| is defined to be |\T1-cmd \foo \T1\foo|,
%    %    where |\T1\foo| is \emph{one} control sequence, not two!
\newcommand

\def\ProvideTextCommand -- same with \providecommand
\@onlypreamble\DeclareTextCommand
\@onlypreamble\DeclareTextSymbol
\gdef\TextSymbolUnavailable#1{%
\@onlypreamble\def\DeclareTextCommandDefault#1{%
\def\ProvideTextCommandDefault#1{%
\def\DeclareTextAccent#1#2#3{%
\def\DeclareTextCompositeCommand#1#2#3#4{%
\@onlypreamble\def\DeclareTextComposite#1#2#3#4{%
\def\UseTextAccent#1#2#3{%
\def\UseTextSymbol#1#2{%
\@onlypreamble\DeclareTextSymbolDefault@item
\@onlypreamble\DeclareTextAccentDefault@item
\def\UndeclareTextCommand#1#2{%

@c Local Variables:
@c ispell-dictionary: "english"
@c End:
