[Vektorweg]

Sorry, i haven't checked in the last days.

I haven't seen exactly the same corresponding monad. But I would compare it with existing backtracking monads used for logic programming. My point is, that a backtracking monad in general is a well known concept. Your special point is the rollback, which isn't included in the monads i saw. I think that people, who worked with backtracking monads, know that they could implement a rollback if needed.