fact: Variable f : sig -> sig.
imports: Undecidability(TM.Util.Prelim) Undecidability(TM.Basic.Mono) Undecidability(TM.Combinators.Combinators) Undecidability(TM.Compound.TMTac) Undecidability(TM.Compound.Multi) Coq(FunInd) Coq(Recdef)