proposition: Lemma subst_term_comp (t : term) sigma tau : t`[sigma]`[tau] = t`[sigma >> subst_term tau].
proof: Proof. induction t; cbn. - reflexivity. - f_equal. rewrite map_map. now apply map_ext_in. 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