proposition: Fact mb_is_pair_fun p q x y : p ≋ ⦃x,y⦄ -> q ≋ ⦃x,y⦄ -> p ≈ q.
proof: Proof. intros H1 H2; red in H1, H2; intro; rewrite H1, H2; tauto. Qed.
imports: List Arith Nat Lia Max Wellfounded Coq.Setoids.Setoid Undecidability.Shared.Libs.DLW.Utils(utils_tac utils_list finite) Undecidability.Shared.Libs.DLW.Vec(pos vec) Undecidability.FOL.TRAKHTENBROT(notations fol_ops fo_sig fo_terms fo_logic)