#K1 elim K1 -K1
[ * /2 width=1 by conj/
#K2 #I2 #L1 #L2 >append_atom >append_bind #H destruct
- >length_bind >append_length >plus_n_Sm
- #H elim (plus_xSy_x_false … H)
+ >length_bind >append_length >nplus_succ_dx
+ #H elim (succ_nplus_refl_sn … H)
| #K1 #I1 #IH *
[ #L1 #L2 >append_bind >append_atom #H destruct
- >length_bind >append_length >plus_n_Sm #H
- lapply (discr_plus_x_xy … H) -H #H destruct
+ >length_bind >append_length >nplus_succ_dx #H
+ lapply (nplus_refl_sn … H) -H #H destruct
| #K2 #I2 #L1 #L2 >append_bind >append_bind #H1 #H2
elim (destruct_lbind_lbind_aux … H1) -H1 #H1 #H3 destruct (**) (* destruct lemma needed *)
elim (IH … H1) -IH -H1 /2 width=1 by conj/
(* Basic_2A1: was: lenv_ind_alt *)
lemma lenv_ind_tail: ∀Q:predicate lenv.
Q (⋆) → (∀I,L. Q L → Q (ⓘ[I].L)) → ∀L. Q L.
-#Q #IH1 #IH2 #L @(f_ind … length … L) -L #x #IHx * //
+#Q #IH1 #IH2 #L @(wf1_ind_nlt … length … L) -L #x #IHx * //
#L #I -IH1 #H destruct
elim (lenv_case_tail … L) [2: * #K #J ]
#H destruct /3 width=1 by/