proposition: Lemma subst_size {ff : falsity_flag} rho phi : size (subst_form rho phi) = size phi.
proof: Proof. revert rho; induction phi; intros rho; cbn; congruence. 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