proposition: Lemma betaEquiv: forall x y z, β (cPair x y) z = Usual.β y x z.
proof: Proof. intros x y z; now rewrite beta_def. Qed.
imports: Coq(Arith) hydras.Ackermann(extEqualNat subAll folProp subProp folReplace folLogic3 NN NNtheory primRec expressible) Coqprime(ChineseRem) Coq(Vector List Lia) hydras(ListExt cPair MoreDecidable) hydras(Compat815 ssrnat_extracts) Coq(Utf8)