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I was wondering what was the cause of the following warning message with the specific \usepackage used below:

Using the following:

Preamble

\documentclass[amssymb,twocolumn,aps]{revtex4}
 \usepackage{times,amsmath,latexsym}

Warning message

Package amsmath Warning: Foreign command \atopwithdelims;
(amsmath)                \frac or \genfrac should be used instead
(amsmath)                 on input line 56.

Line 56

\[ \frac{gcd(m,n)}{n} {n\choose m} \] is an integer for all pairs of integers $n\geq m\geq 1$.

Stefan Kottwitz
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night owl
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1 Answers1

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\atopwithdelims is a TeX math primitive command. If you use amsmath, you don't need \atopwithdelims or \atop, use amsmath macros such as \frac, \binom, \genfrac etc. instead.

If a class or package uses this command, or a command such as \choose which uses it, you would get this warning. I would ignore the warning then, otherwise I would have to redefine the concerned macros of the package or class.

Alternatively, I suggest that you use \binom{a}{n}.

Mensch
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Stefan Kottwitz
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  • Thanks, that is exactly what it is. Using the \choose command for the binomial coefficients. So you suggest ignoring the warning since I am using the \choose ? – night owl Jun 01 '11 at 12:13
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    @night owl: I suggest using \binom{a}{b} instead of {a \choose b}. – Stefan Kottwitz Jun 01 '11 at 12:30
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    @StefanKottwitz Given that you use \choose as an example, would you consider moving the use of \binom{n}{m} into your answer? I suspect many people find their way to this question when using \choose. – Alejandro C De Baca Dec 23 '17 at 05:06