Can some one let me know how to draw diagrams in MO with tikzcd There are information for drawing diagrams using AMScd $\require{AMScd}$ \begin{CD} A @>a>> B\\ @V b V V= @VV c V\\ C @>>d> D \end{CD} but could not find one for tikzcd I want to compile following tikz code. \begin...

I have used presheaf in the past, it's really easy (if you know xypic) and comfortable to use.

&& P\times_{\mathcal{H}_0}Q\ar[rdd]\ar[ldd]\\ \mathcal{G}_1\ar[dd] &&\mathcal{H}_1\ar[dd]&&\mathcal{K}_1\ar[dd]\\ &P\ar[dl]\ar[dr]&&Q\ar[dl]\ar[dr]\\ \mathcal{G}_0&&\mathcal{H}_0&&\mathcal{K}_0 This is the code I have written in http://presheaf.com/ It shows the below diagram I need help ...

I found an older thread from 2013 with basically the same question: Using TikZ on math.stackexchange I'd like to revive the discussion, since I believe it's certainly possible, even if it may not have been back then. That is, can we have TikZ picture rendering? Similar to math formula rendering?...

Definition : Let $\mathcal{G}$ and $\mathcal{H}$ be Lie groupoids. A bibundle from $\mathcal{G}$ to $\mathcal{H}$ is a manifold $P$ together with two maps $a_L:P\rightarrow \mathcal{G}_0,a_R:P\rightarrow \mathcal{H}_0$ such that there is a left action of $\mathcal{G}$ on $P$ with resp...