# How to draw a 2-cell using xymatrix?

How to do something like this

using xymatrix?

• what have you tried, please? there's a very similar example on p.43 of the manual xyrefer.pdf (texdoc xyrefer). that might help. – barbara beeton Jan 26 '17 at 14:27

with tikz-cd (its syntax is to my opinion less cryptic as at xymatrix):

\documentclass[margin=3mm]{standalone}
\usepackage{tikz-cd}

\begin{document}
\begin{tikzcd}
A \ar[r, bend  left=60, ""{name=U}]
\ar[r, bend right=60, ""{name=D,below}]
& B \ar[Rightarrow, from=U, to=D, "\varphi" description]
\end{tikzcd}
\end{document}


for details see tikz-cd documentation, page 8 and 11.

I adding, now, my proposal with xymatrix package.

\documentclass[a4paper,12pt]{standalone}
\usepackage{amsmath,amssymb}
\usepackage[all]{xy}
\begin{document}
\xymatrix@C=1pc@R=1.5pc{
X