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Diffstat (limited to 'Master/texmf-doc/doc/english/FAQ-en/html/FAQ-labundef.html')
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1 files changed, 7 insertions, 7 deletions
diff --git a/Master/texmf-doc/doc/english/FAQ-en/html/FAQ-labundef.html b/Master/texmf-doc/doc/english/FAQ-en/html/FAQ-labundef.html index 2cba86986ff..ba3c6c803b8 100644 --- a/Master/texmf-doc/doc/english/FAQ-en/html/FAQ-labundef.html +++ b/Master/texmf-doc/doc/english/FAQ-en/html/FAQ-labundef.html @@ -2,10 +2,10 @@ <title>UK TeX FAQ -- question label labundef</title> </head><body> <h3>Finding if a label is undefined</h3> -<p>People seem to want to know (at run time) if a label is undefined (I +<p/>People seem to want to know (at run time) if a label is undefined (I don’t actually understand <em>why</em>, particularly: it’s a transient state, and LaTeX deals with it quite well). -<p>A resolved label is simply a command: +<p/>A resolved label is simply a command: <code>\</code><code>r@</code><code><<i>label-name</i>></code>; determining if the label is set is then simply a matter of detecting if the command exists. The usual LaTeX internal way of doing this is to use the command @@ -18,16 +18,16 @@ a <code>\</code><code>label</code> command, and the remaining two arguments are sequences to be used if the label is undefined (<<i>undef-cmds</i>>) or if it is defined (<<i>def-cmds</i>>). -<p>Note that any command that incorporates <code>\</code><code>@ifundefined</code> is naturally +<p/>Note that any command that incorporates <code>\</code><code>@ifundefined</code> is naturally fragile, so remember to create it with <code>\</code><code>DeclareRobustCommand</code> or to use it with <code>\</code><code>protect</code> in a moving argument. -<p>If you’re into this game, you may well not care about LaTeX’s +<p/>If you’re into this game, you may well not care about LaTeX’s warning about undefined labels at the end of the document; however, if you are, include the command <code>\</code><code>G@refundefinedtrue</code> in <<i><code>undef-cmds</i>></code>. -<p>And of course, remember you’re dealing in internal commands, and pay +<p/>And of course, remember you’re dealing in internal commands, and pay attention to the <a href="FAQ-atsigns.html">at-signs</a>. -<p>All the above can be avoided by using the <i>labelcas</i> package: +<p/>All the above can be avoided by using the <i>labelcas</i> package: it provides commands that enable you to switch according to the state of a single label, or the states of a list of labels. The package’s definition is a bit complicated, but the package itself is pretty @@ -35,5 +35,5 @@ powerful. <dl> <dt><tt><i>labelcas.sty</i></tt><dd><a href="ftp://cam.ctan.org/tex-archive/macros/latex/contrib/labelcas.zip">macros/latex/contrib/labelcas</a> (<a href="ftp://cam.ctan.org/tex-archive/macros/latex/contrib/labelcas.tar.gz">gzipped tar</a>, <a href="http://www.tex.ac.uk/tex-archive/macros/latex/contrib/labelcas/">browse</a>) </dl> -<p><p>This question on the Web: <a href="http://www.tex.ac.uk/cgi-bin/texfaq2html?label=labundef">http://www.tex.ac.uk/cgi-bin/texfaq2html?label=labundef</a> +<p/><p>This question on the Web: <a href="http://www.tex.ac.uk/cgi-bin/texfaq2html?label=labundef">http://www.tex.ac.uk/cgi-bin/texfaq2html?label=labundef</a> </body> |