proposition: Lemma is_eset_unique { p : peirce } A x y : binZF <<= A -> A ⊢ is_eset x -> A ⊢ is_eset y -> A ⊢ x ≡' y.
proof: Proof. intros HA H1 H2. apply minZF_ext; auto; now apply is_eset_sub. 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)