(**************************************************************************)
include "Basic_2/substitution/ldrop.ma".
+include "Basic_2/unfold/gr2_minus.ma".
include "Basic_2/unfold/lifts.ma".
(* GENERIC LOCAL ENVIRONMENT SLICING ****************************************)
#L1 #L #L2 #d #e #des #_ #_ #H destruct
qed.
+(* Basic_1: was: drop1_gen_pnil *)
lemma ldrops_inv_nil: ∀L1,L2. ⇩*[⟠] L1 ≡ L2 → L1 = L2.
/2 width=3/ qed-.
/2 width=3/
qed.
+(* Basic_1: was: drop1_gen_pcons *)
lemma ldrops_inv_cons: ∀L1,L2,d,e,des. ⇩*[{d, e} :: des] L1 ≡ L2 →
∃∃L. ⇩*[des] L1 ≡ L & ⇩[d, e] L ≡ L2.
/2 width=3/ qed-.
(* Basic properties *********************************************************)
+(* Basic_1: was: drop1_skip_bind *)
lemma ldrops_skip: ∀L1,L2,des. ⇩*[des] L1 ≡ L2 → ∀V1,V2. ⇧*[des] V2 ≡ V1 →
∀I. ⇩*[des + 1] L1. ⓑ{I} V1 ≡ L2. ⓑ{I} V2.
#L1 #L2 #des #H elim H -L1 -L2 -des