答案1
您可以更改“进”和“出”方向(指南第 1.6 节):
\documentclass[a4paper,12pt]{article}
\usepackage[all,cmtip]{xy}
\begin{document}
\[
\xymatrix{
\Omega \ar[r] \ar@/{}^{2pc}/[r] & \Upsilon \ar[r] & \Psi
}
\]
\[
\xymatrix{
\Omega \ar[r] \ar@(u,u)[r] & \Upsilon \ar[r] & \Psi
}
\]
\end{document}
你可以更好地控制tikz-cd
:
\documentclass[a4paper,12pt]{article}
\usepackage{tikz-cd}
\begin{document}
\[
\begin{tikzcd}
\Omega \arrow[r] \arrow[r,bend left=90] & \Upsilon \ar[r] & \Psi
\end{tikzcd}
\]
\[
\begin{tikzcd}
\Omega \arrow[r] \arrow[r,bend left=90,looseness=1.7] & \Upsilon \ar[r] & \Psi
\end{tikzcd}
\]
\end{document}