48

What is the correct way to make the "does not divide" symbol in plain LaTeX 2e?

I'm talking about the symbol that is a vertical bar with a slash through it. I prefer not to install AMS or other packages, but instead to use plain LaTeX.

migrated from stackoverflow.com Aug 9 '11 at 21:58

This question came from our site for professional and enthusiast programmers.

56

try this:

$x\nmid y$

it's been known to 'save the day'.

  • That doesn't work in plain LaTeX. Do you know what package must be loaded to make it work? I tried \usepackage{amsfonts} but that doesn't work. And I still prefer a plain LaTeX solution. – user448810 Aug 5 '11 at 22:33
  • 5
    I got \nmid working with \usepackage{amssymb}. – user448810 Aug 5 '11 at 22:46
15

Detexify is amazingly helpful in finding any symbol.

4

Using \not with | works with plain LaTeX:

\documentclass{article}
\begin{document}
$2 \not| \;3 $
\end{document}

The symbols \\, and \: and \; create varying degrees of space if the symbols get too close.

  • I wonder why the \not introduces so much space. – Dylan Moreland Jun 22 '12 at 1:11
  • 1
    I'm not sure which space you're talking about but try this: $2 \!\!\not| \,3 $. The \! is negative space to get things closer together on the right and \, will reduce space on the right – DJP Jun 22 '12 at 1:26
  • Oh, I didn't think you'd come back to this! Thanks very much. I just meant that while a|b is nice and compact, a\not|b puts a strange amount of space between a and |. – Dylan Moreland Jun 22 '12 at 1:28
  • I don't know why \not has so much extra space but if I had to guess it might be because \not can be used in conjunction with a lot of other symbols which are wider than | [eg \not\in or \not\subset]. So some combinations will look better than others depending on the symbol width being negated. – DJP Jun 22 '12 at 1:48
  • The spacing on \not\mid was ok when I used it on mathoverflow (mathoverflow.net/questions/256598/…) – David Roberts Dec 7 '16 at 7:41
3

To minimize used packages you can do this:
\newcommand{\ndiv}{\hspace{-4pt}\not|\hspace{2pt}}
From then on \ndiv will add the sign with appropriate spaces before and after.

  • 3
    If the font size changes, this can cause a lot of headache. At least you can opt for units like ex,em but still it would not be robust enough to be used elsewhere. – percusse Nov 27 '12 at 1:11
  • @percusse: can you provide a more robust way? – cxxl May 23 '13 at 8:02
  • @cxxl The answers above are pretty good. Otherwise you can look for the definitions from the LaTeX versions and carry them to plain TeX as raw macros. – percusse May 23 '13 at 20:55

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.