# “Simpler wick” in a split environment and undefined references

When I run

\documentclass{article}
\usepackage{simpler-wick}
\usepackage{amsmath}
\begin{document}
$$\begin{split} x &= \wick{\c a \c b}\\ x &= y\\ \end{split}$$
\end{document}

then the output looks just fine, except that I repeatedly get warning messages

LaTeX Warning: Reference refmathstyle@1' on page 1 undefined on input line 9.
LaTeX Warning: Reference refmathstyle@2' on page 1 undefined on input line 9.

These warning messages go away if I remove the 'split' environment. Is there a way to get rid of these warning messages in a split environment?

• Welcome to TeX.SX! It works fine for me. Which TeX distribution/version do you have? – Phelype Oleinik Mar 14 at 15:19
• @PhelypeOleinik is right... compiled with LaTeX, pdfLaTeX and XeLaTeX of texlive and could not get your warnings... Possibly some more info like your log file is needed here. – koleygr Mar 14 at 15:37
• Yup - you're correct. Running on a distro with everything up to date fixes it. Thanks! – Stringer Mar 18 at 13:27