# delimiter problem with TiKZ

This file gives me the following error message

\documentclass{amsart}
\usepackage{tikz}
\usetikzlibrary{arrows,cd}
\begin{document}
\begin{tikzcd} T \arrow[r,"\langle f,g \rangle"] &  G   \end{tikzcd}
\end{document}

! Missing \endcsname inserted.
\delimiter
l.5 ...,"\langle f,g \rangle"] &  G   \end{tikzcd}


If I change f,g to simply f then it runs fine. But I need f,g for this arrow. How can I get that?

• prblem is comma between f and g. try to envlose them with curly braces: "\langle {f,g} \rangle" – Zarko Jan 4 '18 at 11:42
• @Zarko Yes. Can you make that an answer? – Colin McLarty Jan 4 '18 at 11:50
• done. see answer below. – Zarko Jan 4 '18 at 11:59

options in \arrow[...] are separated by commas. in your case, where you also use comma for separate variables in math expression, you need to encapsulate expression in curly braces. so, instead:
"\langle f,g \rangle"

"\langle {f,g} \rangle"