proposition: Lemma case_analysis x : x = izero \/ exists x', x = iσ x'.
proof: Proof. Proof using M_correct. revert x. apply induction. - now left. - intros x _. right. now exists x. Qed.
imports: PeanoNat Lia Vector Undecidability.SOL(SOL PA2) Undecidability.Shared.Libs.PSL(Vectors) Undecidability.SOL.Util(Syntax Subst Tarski) Undecidability.Synthetic(Definitions DecidabilityFacts EnumerabilityFacts ListEnumerabilityFacts ReducibilityFacts) Undecidability.Shared.Dec