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}
\begin{equation}
\Biggl\{\biggl\{\Bigl\{\bigl\{\{ \qquad \text{stix, commath}
\end{equation}
\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?




commathis essentially a collection of bugs, I wouldn't worry. – egreg Aug 06 '16 at 05:15