proposition: Lemma subst_term_id (t : term) sigma : (forall n, sigma n = var n) -> t`[sigma] = t.
proof: Proof. intros H. induction t; cbn. - now apply H. - f_equal. now erewrite map_ext_in, map_id. Qed.
imports: Undecidability.Synthetic(Definitions DecidabilityFacts EnumerabilityFacts ListEnumerabilityFacts ReducibilityFacts) Undecidability(Shared.ListAutomation Shared.Dec) Coq(Eqdep_dec PeanoNat Nat) Coq.Vectors.Vector Undecidability.Shared.Libs.PSL.Vectors(Vectors) EqdepFacts