Add support for unsupported commands

[stromdotcom]

I am having an issue where latex rendering fails if the latex contains \pmod{n} or \mod{n} (or any other unsupported command). I can stop the failure by adding the following:

MTMathAtomFactory.add(latexSymbol: "pmod", value: MTMathAtomFactory.operatorWithName("pmod", limits: false))

however this doesn't really do anything except replace \pmod with pmod. It should render something like (mod n).

These two commands are apparently part of the amsmath package. Is it possible to add support for additional packages?