Recursively applies a function f to a proof.
Recursively applies a function f to a proof.
In the case of an axiom p, the result is just f(p).
In the case of a unary proof p with subproof u, this means that it recursively applies f to u, giving u', and then computes f(p(u')). Binary proofs work analogously.
Caveat: It might mess up the ancestor relation on formula occurrences, so be careful.
A function of type LKProof => LKProof
An LKProof
Maybe there is a better place for this?