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diff --git a/Master/texmf-doc/doc/english/FAQ-en/html/FAQ-nodollar.html b/Master/texmf-doc/doc/english/FAQ-en/html/FAQ-nodollar.html new file mode 100644 index 00000000000..ab7876b5e36 --- /dev/null +++ b/Master/texmf-doc/doc/english/FAQ-en/html/FAQ-nodollar.html @@ -0,0 +1,29 @@ +<head> +<title>UK TeX FAQ -- question label nodollar</title> +</head><body> +<h3>"Missing <code>$</code> inserted"</h3> +<p>There are certain things that <em>only</em> work in maths mode. If your +document is not in maths mode and you have an <code>_</code> or a <code>^</code> character, +TeX (and by inheritance, LaTeX too) will say +<pre> +! Missing $ inserted +</pre> +as if you couldn't possibly have misunderstood the import of what you +were typing, and the only possible interpretation is that you had +commited a typo in failing to enter maths mode. TeX, therefore, +tries to patch things up by inserting the <code>$</code> you 'forgot', so that +the maths-only object will work; as often as not this will land you in +further confusion. +<p>It's not just the single-character maths sub- and superscript +operators: anything that's built in or declared as a maths operation, +from the simplest lower-case <code>\</code><code>alpha</code> through the inscrutable +<code>\</code><code>mathchoice</code> primitive, and beyond, will provoke the error if +misused in text mode. +<p>LaTeX offers a command <code>\</code><code>ensuremath</code>, which will put you in maths +mode for the execution of its argument, if necessary: so if you want +an <code>\</code><code>alpha</code> in your running text, say +<code>\</code><code>ensuremath{<code>\</code><code>alpha</code>}</code>; if the bit of running text somehow +transmutes into a bit of mathematics, the <code>\</code><code>ensuremath</code> will become +a no-op, so it's pretty much always safe. +<p><p>This question on the Web: <a href="http://www.tex.ac.uk/cgi-bin/texfaq2html?label=nodollar">http://www.tex.ac.uk/cgi-bin/texfaq2html?label=nodollar</a> +</body> |