# intriguing stix commath conflict

I've encountered a curious issue with commath and stix the cause of which I do not understand. Consider

\documentclass[12pt]{article}

\usepackage{stix}
%\usepackage{amsmath}
\usepackage{commath}

\begin{document}
$$\Biggl\{\biggl\{\Bigl\{\bigl\{\{ \qquad \text{stix, commath}$$
\end{document}


This gives the following output, depending on which combination of packages is included. Notice \big\{ versus \Big\{ (third and fourth symbol). In short, stix and commath appear not to work together nicely. What is the cause of this?

I know how to fix the problem using a solution for a different problem found elsewhere. But what can cause the bug I'm describing here?

• Since commath is essentially a collection of bugs, I wouldn't worry. – egreg Aug 6 '16 at 5:15
• just don't load commath – David Carlisle Aug 6 '16 at 7:27
• Now those are ringing endorsements! 😃 – JPi Aug 6 '16 at 8:29