# Creating Direct Limits and Inverse Limits using Tikz

I am trying to make something that looks like

I am trying to go from here (works):

\begin{tikzcd}
A \arrow{r}\arrow{rd}
&B \arrow{d}\arrow[leftarrow]{r}
&C \arrow{ld}\\
&D
\end{tikzcd}


to here (doesn't work):

\begin{tikzcd}
A \arrow{r}\arrow{rd} \arrow{rdd}
&B \arrow{d}\arrow[leftarrow]{r}
&C \arrow{ld} \arrow{ldd} \\
&D
&E\\
\end{tikzcd}


I try many combinations but don't see how the tikz@x-y-z values work. Any help is appreciated.

Thanks,

Brian

You have to use three columns.

\documentclass{article}
\usepackage{tikz-cd}

\begin{document}

$\begin{tikzcd}[row sep=4em] X_{i} \arrow[rr,"f_{ij}"] \arrow[dr,"\phi_{i}"] \arrow[ddr,swap,end anchor={[xshift=0.2em]north west},"\psi_{i}"] && X_{j} \arrow[dl,swap,"\phi_{j}"] \arrow[ddl,end anchor={[xshift=-0.2em]north east},"\psi_{j}"] \\ & X \arrow[d,"u"] \\ & Y \end{tikzcd}$

\end{document}


The end anchor are just to avoid the arrow ends to be too near to each other.

• For inverse limit, just dualize, of course. ;-) – egreg Jul 25 '14 at 20:49