Test commutative diagram drawing with MathJax

I use xyjax which is xy-pic extension for MathJax.

\[\xymatrix { U \ar@/_/[ddr]_y \ar@{.>}[dr]|{\langle x,y \rangle} \ar@/^/[drr]^x \\ & X \times_Z Y \ar[d]^q \ar[r]_p & X \ar[d]_f \\ & Y \ar[r]^g & Z }\] \[\begin{xy} \xymatrix { U \ar@/_/[ddr]_y \ar@{.>}[dr]|{\langle x,y \rangle} \ar@/^/[drr]^x \\ & X \times_Z Y \ar[d]^q \ar[r]_p & X \ar[d]_f \\ & Y \ar[r]^g & Z } \end{xy}\] \[\xymatrix{A \ar@{}[dr]|{=} \ar[d] \ar[r] & B \ar[d] \\ B \ar[r] & C }\]

Here is the User guide how to use xy-pic.