fact: Fixpoint open_exp_wrt_exp_rec (k:nat) (e_5:exp) (e__6:exp) {struct e__6}: exp := match e__6 with | (var_b nat) => match lt_eq_lt_dec nat k with | inleft (left _) => var_b nat | inleft (right _) => e_5 | inright _ => var_b (nat - 1) end | (var_f x) => var_f x | (abs e) => abs (open_exp_wrt_exp_rec (S k) e_5 e) | (app e1 e2) => app (open_exp_wrt_exp_rec k e_5 e1) (open_exp_wrt_exp_rec k e_5 e2) end.
imports: Metalib.Metatheory