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0003 <!-- This document is an unofficial reference manual for LaTeX, a
0004 document preparation system, version of November 2018.
0005 
0006 This manual was originally translated from LATEX.HLP v1.0a in the
0007 VMS Help Library.  The pre-translation version was written by
0008 George D. Greenwade of Sam Houston State University.  The
0009 LaTeX 2.09 version was written by Stephen Gilmore.  The
0010 LaTeX2e version was adapted from this by Torsten Martinsen.  Karl
0011 Berry made further updates and additions, and gratefully acknowledges
0012 using Hypertext Help with LaTeX, by Sheldon Green, and
0013 LaTeX Command Summary (for LaTeX 2.09) by
0014 L. Botway and C. Biemesderfer (published by the TeX Users
0015 Group as TeXniques number 10), as reference material.  We also
0016 gratefully acknowledge additional material appearing in
0017 latex2e-reference by Martin Herbert Dietze.  (From these references no
0018 text was directly copied.)
0019 
0020 Copyright 2007, 2008, 2009, 2010, 2011, 2012, 2013,
0021 2014, 2015, 2016, 2017, 2018 Karl Berry.
0022 
0023 Copyright 1988, 1994, 2007 Stephen Gilmore.
0024 
0025 Copyright 1994, 1995, 1996 Torsten Martinsen.
0026 
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0032 Permission is granted to copy and distribute modified versions of this
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0115 <p>
0116 Next: <a href="_005csubsection.html#g_t_005csubsection" accesskey="n" rel="next">\subsection</a>, Previous: <a href="_005cchapter.html#g_t_005cchapter" accesskey="p" rel="prev">\chapter</a>, Up: <a href="Sectioning.html#Sectioning" accesskey="u" rel="up">Sectioning</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="IndexDocument.html#Index" title="Index" rel="index">Index</a>]</p>
0117 </div>
0118 <hr>
0119 <a name="g_t_005csection-1"></a>
0120 <h3 class="section">6.3 <code>\section</code></h3>
0121 
0122 <a name="index-_005csection-1"></a>
0123 <a name="index-section-1"></a>
0124 
0125 <p>Synopsis, one of:
0126 </p>
0127 <div class="example">
0128 <pre class="example">\section{<var>title</var>}
0129 \section*{<var>title</var>}
0130 \section[<var>toc-title</var>]{<var>title</var>}
0131 </pre></div>
0132 
0133 <p>Start a section.  The standard LaTeX classes <code>article</code>,
0134 <code>book</code>, and <code>report</code> all have this command.
0135 </p>
0136 <p>This produces a section.
0137 </p>
0138 <div class="example">
0139 <pre class="example">In this Part we tend to be more interested in the function,
0140 in the input-output behavior,
0141 than in the details of implementing that behavior.
0142 
0143 \section{Turing machines}
0144 Despite this desire to downplay implementation,
0145 we follow the approach of A~Turing that the
0146 first step toward defining the set of computable functions
0147 is to reflect on the details of what mechanisms can do.
0148 </pre></div>
0149 
0150 <p>For the standard LaTeX classes <code>book</code> and <code>report</code> the
0151 default output is like &lsquo;<samp>1.2 <var>title</var></samp>&rsquo; (for chapter&nbsp;1,
0152 section&nbsp;2), alone on its line and flush left, in boldface and a
0153 larger type (the type size is <code>\Large</code>).  The same holds in
0154 <code>article</code> except that there are no chapters in that class so it
0155 looks like &lsquo;<samp>2 <var>title</var></samp>&rsquo;.
0156 </p>
0157 <p>The <code>*</code>&nbsp;form shows <var>title</var>.
0158 But it does not show the section number, does not increment the
0159 <code>section</code> counter, produces no table of contents entry, and does
0160 not affect the running header.  (If you use the page style
0161 <code>headings</code> in a two-sided document then the header will be from the
0162 prior section.)
0163 </p>
0164 <p>The optional argument <var>toc-title</var> will appear as the section title
0165 in the table of contents (see <a href="Table-of-contents-etc_002e.html#Table-of-contents-etc_002e">Table of contents etc.</a>) and in
0166 running headers (see <a href="Page-styles.html#Page-styles">Page styles</a>).  If it is not present then
0167 <var>title</var> will be there.  This shows the full name in the title of the
0168 section,
0169 </p>
0170 <div class="example">
0171 <pre class="example">\section[Elizabeth~II]{Elizabeth the Second,
0172   by the Grace of God of the United Kingdom,
0173   Canada and Her other Realms and Territories Queen,
0174   Head of the Commonwealth, Defender of the Faith.}
0175 </pre></div>
0176 
0177 <p>but only &lsquo;<samp>Elizabeth II</samp>&rsquo; on the contents page and in the headers.
0178 This has a line break in <var>title</var> but that does not work with headers
0179 so it is omitted from the contents and headers.
0180 </p>
0181 <div class="example">
0182 <pre class="example">\section[Truth is, I cheated; my life story]{Truth is,
0183   I cheated\\my life story}
0184 </pre></div>
0185 
0186 <p>For determining which sectional units are numbered and which appear in
0187 the table of contents, the level number of a section is&nbsp;1
0188 (see <a href="Sectioning.html#Sectioning_002fsecnumdepth">Sectioning/secnumdepth</a> and see <a href="Sectioning.html#Sectioning_002ftocdepth">Sectioning/tocdepth</a>).
0189 </p>
0190 <a name="index-package_002c-indentfirst-2"></a>
0191 <a name="index-indentfirst-package-2"></a>
0192 
0193 <p>The paragraph that follows the section title is not indented, as is a
0194 standard typographical practice.  One way to get an indent is to use the
0195 package <samp>indentfirst</samp>.
0196 </p>
0197 <a name="index-package_002c-titlesec-3"></a>
0198 <a name="index-titlesec-package-3"></a>
0199 
0200 <p>In general, to change the behavior of the <code>\section</code> command, there
0201 are a number of options.  One is the <code>\@startsection</code> command
0202 (see <a href="_005c_0040startsection.html#g_t_005c_0040startsection">\@startsection</a>).  There are also many packages on CTAN that
0203 address this, including <samp>titlesec</samp>.  See the documentation but the
0204 example below gives a sense of what they can do.
0205 </p>
0206 <div class="example">
0207 <pre class="example">\usepackage{titlesec}   % in preamble
0208 \titleformat{\section}
0209   {\normalfont\Large\bfseries}  % format of title
0210   {\makebox[1pc][r]{\thesection\hspace{1pc}}} % label
0211   {0pt}                   % length of separation between label and title
0212   {}                      % before-code hook
0213 \titlespacing*{\section}
0214   {-1pc}{18pt}{10pt}[10pc]
0215 </pre></div>
0216 
0217 <p>That puts the section number in the margin.
0218 </p>
0219 
0220 
0221 
0222 <hr/><div class='referenceinfo'> <a href='https://latexref.xyz/'> <i>Unofficial LaTeX2e reference manual</i></a></div>
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