proposition: Lemma impTrans (T : System) (f g h : Formula): SysPrf T (f -> g)%nt -> SysPrf T (g -> h)%nt -> SysPrf T (f -> h)%nt.
proof: Proof. apply (impTrans LNT). Qed.
imports: Coq(Arith Ensembles List) hydras.Ackermann(Languages folProof folProp folLogic3)