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