# Incompatibility between isomath and \operatorname

The following MWE lead to an obvious problem:

\documentclass{amsart}
\usepackage{isomath}
\newcommand{\foo}{\operatorname{\alpha}}
\begin{document}
$\foo$
\end{document}


How do I avoid this conflict?

• How important is it to you to use the isomath package? Put differently, are you open to using LuaLaTeX and the unicode-math package? – Mico Jun 27 '18 at 6:45
• In a perfect world, ArXiv would allow LuaLaTeX :/ – Damien L Jun 27 '18 at 7:03
• But \operatorname is only intended for log-like operators, not other symbols. What is you use case? – Andrew Swann Jun 27 '18 at 7:54

<rant>
Since ISO norms change so many conventions used for centuries in mathematics to establish some silly rules, it is expected that isomath does weird things.
</rant>

Here is a workaround: Greek letters can be set as \mathnormal.

\documentclass{amsart}
\usepackage{isomath}

\newcommand{\foo}{\operatorname{\mathnormal{\alpha}}}
\DeclareMathOperator{\baz}{\mathnormal{\alpha}}

\begin{document}

$\foo\baz$

\end{document}


A possible situation where one might want it:

\documentclass{amsart}
\usepackage{isomath}

\DeclareMathOperator*{\amax}{\mathnormal{\alpha}-max}

\begin{document}

$\amax_{x\in[0,1]} f(x)=\beta$

\end{document}


isomath (more precisely fixmath) redefines the greek symbols. Assuming that you use the package because you want this change, you probably should define your own greek symbols to use them inside \operatorname:

\documentclass{amsart}

\usepackage{isomath}

%found in fontmath.ltx
\DeclareMathSymbol{\opalpha}{\mathord}{letters}{"0B}
\DeclareMathSymbol{\opGamma}{\mathalpha}{operators}{"00}

\newcommand{\foo}{\operatorname{\opalpha\opGamma}}
\begin{document}
$\foo \neq \alpha\Gamma$
\end{document}