In general, it seems that formal language theory questions (uncommon as they are on the site) tend *not* to be closed down, although I have seen users vote to close such questions (unfortunately I do not recall which questions it was).

Personally I think that in general, formal language theory questions (say, questions about reducing grammar to Chomsky normal form, or the pumping thingy) do not belong on this SE unless they are applied to natural languages in some way.

Firstly, [theoretical computer science](https://cstheory.stackexchange.com/) folks should be in a better position to answer such questions than linguists anyway. Since cross-posting is discouraged, it would benefit the asker to ask at CS theory, rather than here.

Secondly, linguistics is the empirical study of *natural* language. While formal languages are sometimes used to model natural languages, they are not themselves part of linguistics any more than Markov chains or information theory, even though the former has wide applications in computational linguistics and the latter in corpus and functional linguistics.

Do you agree that formal language theory should be off-topic on this site?