proposition: Lemma minZF_sym { p : peirce } A x y : binZF <<= A -> A ⊢ x ≡' y -> A ⊢ y ≡' x.
proof: Proof. intros HA H. prv_all' z. apply (AllE z) in H. cbn in H. subsimpl_in H. apply CE in H. apply CI; tauto. Qed.
imports: Undecidability.FOL.Syntax.Facts Undecidability.FOL.Syntax.Asimpl Undecidability.FOL.Semantics.Tarski.FullFacts Undecidability.FOL.Deduction.FullNDFacts Undecidability.FOL.Sets(binZF ZF) Undecidability.FOL.Reductions.PCPb_to_ZF Undecidability(Shared.ListAutomation) Morphisms Undecidability.FOL(Reductions.PCPb_to_ZFeq)