+++ /dev/null
-(**************************************************************************)
-(* ___ *)
-(* ||M|| *)
-(* ||A|| A project by Andrea Asperti *)
-(* ||T|| *)
-(* ||I|| Developers: *)
-(* ||T|| The HELM team. *)
-(* ||A|| http://helm.cs.unibo.it *)
-(* \ / *)
-(* \ / This file is distributed under the terms of the *)
-(* v GNU General Public License Version 2 *)
-(* *)
-(**************************************************************************)
-
-include "basic_2/syntax/lenv.ma".
-
-(* LENGTH OF A LOCAL ENVIRONMENT ********************************************)
-
-rec definition length L ≝ match L with
-[ LAtom ⇒ 0
-| LBind L _ ⇒ ↑(length L)
-].
-
-interpretation "length (local environment)" 'card L = (length L).
-
-(* Basic properties *********************************************************)
-
-lemma length_atom: |⋆| = 0.
-// qed.
-
-(* Basic_2A1: uses: length_pair *)
-lemma length_bind: ∀I,L. |L.ⓘ{I}| = ↑|L|.
-// qed.
-
-(* Basic inversion lemmas ***************************************************)
-
-lemma length_inv_zero_dx: ∀L. |L| = 0 → L = ⋆.
-* // #L #I >length_bind
-#H destruct
-qed-.
-
-lemma length_inv_zero_sn: ∀L. 0 = |L| → L = ⋆.
-/2 width=1 by length_inv_zero_dx/ qed-.
-
-(* Basic_2A1: was: length_inv_pos_dx *)
-lemma length_inv_succ_dx: ∀n,L. |L| = ↑n →
- ∃∃I,K. |K| = n & L = K. ⓘ{I}.
-#n *
-[ >length_atom #H destruct
-| #L #I >length_bind /3 width=4 by ex2_2_intro, injective_S/
-]
-qed-.
-
-(* Basic_2A1: was: length_inv_pos_sn *)
-lemma length_inv_succ_sn: ∀n,L. ↑n = |L| →
- ∃∃I,K. n = |K| & L = K. ⓘ{I}.
-#n #L #H lapply (sym_eq ??? H) -H
-#H elim (length_inv_succ_dx … H) -H /2 width=4 by ex2_2_intro/
-qed-.
-
-(* Basic_2A1: removed theorems 1: length_inj *)