File:Inverse System Morphism.svg

%Note: Add the -shell-escape flag to the compilation command to compile directly to an image. 
%For .pdf files, use \documentclass[preview]{standalone}
%For .png files, (see http://tex.stackexchange.com/q/11866 for more info) use: \documentclass[convert={density=300,size=1080x800,outext=.png}]{standalone}
%For .svg files you need pdf2svg installed (see https://tex.stackexchange.com/a/51766/187911 for more info) use:
\documentclass[convert={outext=.svg,command=\unexpanded{pdf2svg \infile\space\outfile}},multi=false]{standalone}
\usepackage{tikz}
\usetikzlibrary{matrix,arrows,decorations.pathmorphing}
\usepackage[all]{xy}
\begin{document}
\begin{tikzpicture}[scale=2.5]
\node (MIOTAA) at (0,1) {$M_{\iota(a)}$};
\node (MIOTAB) at (1.5,1) {$M_{\iota(b)}$};
\node (NA)     at (0,0) {$N_a$};
\node (NB)     at (1.5,0) {$N_b$};
\node (MINF)   at (3,1) {$M$};
\node (NINF)   at (3,0) {$N$};
\path[->,font=\scriptsize,>=angle 90]
(MIOTAB) edge node[above]{\scalebox{1.5}{$\mu_{\iota(a) \iota(b)}$}} (MIOTAA)
(MIOTAA) edge node[right]{\scalebox{1.5}{$F_{a}$}} (NA)
(MIOTAB) edge node[right]{\scalebox{1.5}{$F_{b}$}} (NB)
(NB)     edge node[above]{\scalebox{1.5}{$\nu_{ab}$}} (NA)
(MINF)   edge node[above]{\scalebox{1.5}{$\mu_{\iota(b)}$}} (MIOTAB)
(MINF)   edge node[right]{\scalebox{1.5}{$F_{\infty}$}} (NINF)
(NINF)   edge node[above]{\scalebox{1.5}{$\nu_b$}} (NB);
\end{tikzpicture}
\end{document}