On Sat, Feb 25, 2012 at 9:11 AM, Davide P. Cervone <
dp...@union.edu> wrote:
> Victor already mentioned xyjax. But simple diagrams can be done using the
> array environment, for example
>
> \require{AMSmath} \def\mapright#1{\xrightarrow{#1}}
> \def\mapdown#1{\Big\downarrow\rlap{\raise2pt{\scriptstyle{#1}}}}
> \begin{array}{ccc} A& \mapright{f} & B \\[3pt] \mapdown{g} & & \mapdown{g'}
> \\ A^*& \mapright{f^*} & B^* \end{array}\phantom{h}
>
> (Note that the \\[3pt] requires MathJax v2.0 to be handled properly. Just
> leave these off for MathJax v1.1.)
>
> Davide
Unfortunately stretched diagonal arrows seem to be unavailable.