Using Computer Modern symbols in math mode in Minion Pro

Question

I'm using Minion Pro for my thesis but I would like to use some Computer Modern symbols in math mode for some symbols. I don't particularly like the \partial or \int or \in or \sum symbols, as in here:

and would prefer to use Computer Modern. Is there some global option or package to use CM fonts in math mode for specific symbols like the ones above? I want to keep the other letters and numbers in Minion Pro. I know this has been done before but after much searching I haven't been able to find a way to do this. I'm using pdflatex on TexStudio.

Thanks in advance!

Answer 1

It's not at all difficult. According to fontmath.ltx we have

\DeclareMathSymbol{\sum}{\mathop}{largesymbols}{"50}
\DeclareMathSymbol{\intop}{\mathop}{largesymbols}{"52}
\DeclareMathSymbol{\in}{\mathrel}{symbols}{"32}
\DeclareMathSymbol{\partial}{\mathord}{letters}{"40}

First we need to have available the necessary math symbol fonts and we find

\DeclareSymbolFont{letters}     {OML}{cmm} {m}{it}
\DeclareSymbolFont{symbols}     {OMS}{cmsy}{m}{n}
\DeclareSymbolFont{largesymbols}{OMX}{cmex}{m}{n}

We can't call them the same, because the symbolic names are preempted by the font package you're using for Minion. So you can add

\makeatletter
\AtBeginDocument{%
  \DeclareSymbolFont{CMletters}     {OML}{cmm} {m}{it}%
  \DeclareSymbolFont{CMsymbols}     {OMS}{cmsy}{m}{n}%
  \DeclareSymbolFont{CMlargesymbols}{OMX}{cmex}{m}{n}%
  %
  \let\sum\relax\let\intop\relax\let\in\relax\let\partial\relax
  \DeclareMathSymbol{\sum}{\mathop}{CMlargesymbols}{"50}%
  \DeclareMathSymbol{\intop}{\mathop}{CMlargesymbols}{"52}%
  \DeclareMathSymbol{\in}{\mathrel}{CMsymbols}{"32}%
  \DeclareMathSymbol{\partial}{\mathord}{CMletters}{"40}%
  \DeclareMathSymbol{\CMslash}{\mathord}{CMletters}{"3D}%
  \DeclareRobustCommand\notin{\mathrel{\m@th\mathpalette\c@ncel\in}}%
  \renewcommand\c@ncel[2]{%
    \m@th\ooalign{$\hfil#1\mkern1mu\CMslash\hfil$\crcr$#1#2$}%
  }%
}
\makeatother

Note that changing \in would make \notin to become wrong, so I added also the necessary corrections.

Here's a test, where I used kpfonts instead of Minion that I don't have. The differences are still well noticeable.

\documentclass{article}
\usepackage{kpfonts}

\makeatletter
\AtBeginDocument{%
  \DeclareSymbolFont{CMletters}     {OML}{cmm} {m}{it}%
  \DeclareSymbolFont{CMsymbols}     {OMS}{cmsy}{m}{n}%
  \DeclareSymbolFont{CMlargesymbols}{OMX}{cmex}{m}{n}%
  %
  \let\sum\relax\let\intop\relax\let\in\relax\let\partial\relax
  \DeclareMathSymbol{\sum}{\mathop}{CMlargesymbols}{"50}%
  \DeclareMathSymbol{\intop}{\mathop}{CMlargesymbols}{"52}%
  \DeclareMathSymbol{\in}{\mathrel}{CMsymbols}{"32}%
  \DeclareMathSymbol{\partial}{\mathord}{CMletters}{"40}%
  \DeclareMathSymbol{\CMslash}{\mathord}{CMletters}{"3D}%
  \DeclareRobustCommand\notin{\mathrel{\m@th\mathpalette\c@ncel\in}}%
  \renewcommand\c@ncel[2]{%
    \m@th\ooalign{$\hfil#1\mkern1mu\CMslash\hfil$\crcr$#1#2$}%
  }%
}
\makeatother

\begin{document}
\[
\sum_{i=1}^n\int_0^1 \frac{\partial f}{\partial y}(x)\,dx\in X \notin \mathcal{Y}
\]
\end{document}

Output with the redefinitions

Output without the redefinitions