![如何绘制模块同态图?](https://linux22.com/image/411550/%E5%A6%82%E4%BD%95%E7%BB%98%E5%88%B6%E6%A8%A1%E5%9D%97%E5%90%8C%E6%80%81%E5%9B%BE%EF%BC%9F.png)
答案1
只是为了好玩...对不起...Sigur 和 cp
\documentclass[a4paper,12pt]{article}
\usepackage{tikz-cd}
\usepackage{amssymb}
\begin{document}
\begin{tikzcd}[column sep=1.5pt]
& M_1\times M_2 \arrow[dd, "h"'] \arrow[rd, "\pi_2"] &\\
0\to M_1 \arrow[ru, "i_1"] \arrow[rd, "f_1"'] & & M_2\to 0 \\
& M \arrow[ru, "g_2"'] &
\end{tikzcd}
\end{document}