(* Properties with iterated push ********************************************)
lemma isfin_pushs: ∀n,f. 𝐅❪f❫ → 𝐅❪⫯*[n]f❫.
-#n elim n -n /3 width=3 by isfin_push/
+#n @(nat_ind_succ … n) -n /3 width=3 by isfin_push/
qed.
(* Inversion lemmas with iterated push **************************************)
lemma isfin_inv_pushs: ∀n,g. 𝐅❪⫯*[n]g❫ → 𝐅❪g❫.
-#n elim n -n /3 width=3 by isfin_inv_push/
+#n @(nat_ind_succ … n) -n /3 width=3 by isfin_inv_push/
qed.
(* Properties with tail *****************************************************)
(* Inversion lemmas with iterated tail **************************************)
lemma isfin_inv_tls: ∀n,f. 𝐅❪⫱*[n]f❫ → 𝐅❪f❫.
-#n elim n -n /3 width=1 by isfin_inv_tl/
+#n @(nat_ind_succ … n) -n /3 width=1 by isfin_inv_tl/
qed-.