# tikz-cd error trying to typeset a “three storey” diagram

I'm trying to typeset the diagram that describes the axiom of invertibility in a group. Here's my code:

$$\label{diag:inv} \begin{tikzcd}[column sep=large] G\times G\arrow{rr}{\id\times\iota} %\id=\operatorname{id} \arrow{dd}[swap]{\iota\times\id}\arrow{dr}{*} &G\times G \arrow{dd}{m}\arrow{dl}{*}\\ & &\{*\} \arrow{dr}{O}&\\ %THIS LINE DOESN'T WORK G\times G \arrow{rr}{m}\arrow{ur}{*} &G \end{tikzcd}$$


I've tried typesetting without the ampersands in the line that doesn't work to no avail. The diagram typesets fine without that line and replacing 'rr' by 'r' etc. in the arrow direction parameter. I get the following error: I can't find file 'tikzlibraryquotes.code.tex' \usetikzlibrary{matrix,quotes,arrows.meta}. I've placed a copy of tikzlibrarycd.code.tex in my document folder (as specified in the documentation available on CTAN for "non-orthodox" use of the package).

Any ideas? Thanks mates!!

I got it!

The problem was the first and third "storeys" didn't have the same number of "windows" as the second. Here's the working code. And it doesn't need the copy of tikzlibrarycd.code.tex in the CWD.

G\times G\arrow{dd}[swap]{\iota\times\id}\arrow{rr}{\id\times\iota}\arrow{dr}{*}
&\empty
&G\times G\arrow{dd}{m}\arrow{dl}{*}\\
\empty
&\{*\}\arrow{dr}{e}
&\empty\\
G\times G\arrow{rr}[swap]{m}\arrow{ur}{*}
&\empty
&G

• You do not need all those \emptys as you have no arrow pointing to there. – LaRiFaRi Feb 25 '16 at 9:41
• LaRiFaRi: I know that, they're there for my mental well-being :) – Óscar Guajardo Feb 25 '16 at 22:46