proposition: Lemma M_adj x y z : x ∈ y ::: z <-> x = y \/ x ∈ z.
proof: Proof. Proof using M_FST VIEQ. rewrite <- VIEQ. apply (@M_FST (fun _ => ∅) ax_adj). cbn; tauto. Qed.
imports: Undecidability.FOL(Syntax.Facts Semantics.Tarski.FullFacts FST) Undecidability.FOL(Sets.FST) Undecidability.FOL.TRAKHTENBROT(hfs) Undecidability.Shared.Libs.DLW.Utils(finite) Undecidability(Shared.ListAutomation) Coq(Lia)