Are your recursive PDA's as powerful as a Turing machine? Are regular expression edges supported?

[enjoysmath]

According to this thread: Computer Science SE thread

two PDA's or also a 2-stack PDA are as powerful as a single Turing machine. So I was wondering, since you've got support for recursivity, then also are yours as powerful as a Turing machine?

Not really, a high-priority question. I'm pretty sure I don't have to worry about it so much and can amend any issues should my system run into lack of expressivity in the future. I'm making a sort of "math state machine" that tries to understand a mixture of English and LaTeX formulae.

I'm using TextBlob to break a user's input into parts-of-speech. How does your library fare with regular expressions on transition edges? I either need that or some equivalent method so that I can effectively handle variable substitutions. So that users can choose whatever variables make sense to a particular context, but then a user can use the statemachine with whatever variables make sense to their "calling context".