fact: Fixpoint idSubst_exp (sigmaexp : fin -> exp ) (Eqexp : forall x, sigmaexp x = (var_exp ) x) (s : exp ) : subst_exp sigmaexp s = s := match s with | var_exp s => Eqexp s | const s0 => congr_const (eq_refl s0) | lam s0 => congr_lam (idSubst_exp (up_exp_exp sigmaexp) (upId_exp_exp (_) Eqexp) s0) | app s0 s1 => congr_app (idSubst_exp sigmaexp Eqexp s0) (idSubst_exp sigmaexp Eqexp s1) end.
imports: Undecidability.HOU(std.std)