Fraction in pmod bracket

Question

I want to put a fraction into the pmod brackets in math mode, i.e

documentclass{article}
usepackage{amsmath}
begin{document}
[xequiv ypmod{frac{a}{b}}]
end{document}

However, the brackets don't become bigger, just like

left( right)

to fit with the fraction. How to fix it?

Srijon Sarkar · Answer

The below thing also works fine, though its bmod, and not pmod, still
text{something} equiv 13 left(bmod dfrac{545ell^{45}}{541p^P{p-1}}right)

Output:

egreg · Answer

You can use the approach of mathtools with DeclarePairedDelimiter:

documentclass{article}
usepackage{amsmath,mathtools,xparse}

DeclarePairedDelimiterparens{(}{)}
makeatletter
RenewDocumentCommand{pod}{sO{}m}{%
  allowbreak
  if@display
    mkern 18mu
  else
    mkern 8mu
  fi
  IfBooleanTF{#1}{parens*{#3}}{parens[#2]{#3}}%
}
RenewDocumentCommand{pmod}{sO{}m}{%
  IfBooleanTF{#1}
    {pod*{{operator@font mod}mkern 6mu#3}}
    {pod[#2]{{operator@font mod}mkern 6mu#3}}%
}

begin{document}
[
xequiv ypmod*{frac{a}{b}}
]
[
xequiv ypmod[Big]{frac{a}{b}}
]
end{document}

Note that you can use pod with the same syntax as well (which omits the “mod”).

Fraction in pmod bracket

2 Answers

Add your own answers!

Ask a Question