[hokkos]

I think AutomataDotNet can do all that :

Automation of regular expression generation, it seems easy : use RE fragments and aggregate them, or walk the type hierarchy of the RE AST and generate them randomly.

B needs to guess A's RE so we need to generate examples of strings belonging to it to gives hints : this is exactly the use case of AutomataDotNet.

Also if B guess a RE that is equivalent to A's RE it seems unfair to not attribute a win, so we need to tell if 2 RE belong to the same equivalence class. AutomataDotNet does have a AreEquivalent method.

You can automate the generation of false positive and a false negative with the method Minus to creates an automaton that accepts A-B or B-A and generate an example.

[eru]

Thanks, I'll have a look.

You are right about the equivalence classes: for that you want to talk about the corresponding DFA (which have a unique normal form in the shape of the minimum DFA).

I am not sure about the rest of what you are saying: in general even just minimizing regular expressions is EXP-SPACE complete, if I remember right.

Yes, generation of false negative and false positive ain't so hard---theory agrees with you. But automating the guesser is, as far as I know.

[hokkos]

I was talking about generating hints to give an opportunity to the RE guesser to find the secret RE. You seem to talk about automating the RE generation based on the pattern of the hints, yeah I didn't thought about that, the other answer seem to talk about it.