proposition: Lemma up_funcomp sigma tau : forall n, (up sigma >> subst_term (up tau)) n = up (sigma >> subst_term tau) n.
proof: Proof. intros [|]; cbn; trivial. setoid_rewrite subst_term_comp. apply subst_term_ext. now intros [|]. 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