update in ground_2, static_2, basic_2

[helm.git] / matita / matita / contribs / lambdadelta / static_2 / static / rdeq_drops.ma

diff --git a/matita/matita/contribs/lambdadelta/static_2/static/rdeq_drops.ma b/matita/matita/contribs/lambdadelta/static_2/static/rdeq_drops.ma
index 6b9537f61add366ff1fdb87a4044a1b1c1d95bb6..825ed84d94b644a26ba529e6551beae43943a821 100644 (file)
--- a/matita/matita/contribs/lambdadelta/static_2/static/rdeq_drops.ma
+++ b/matita/matita/contribs/lambdadelta/static_2/static/rdeq_drops.ma
@@ -28,11 +28,9 @@ lemma rdeq_lifts_sn: ∀h,o. f_dedropable_sn (cdeq h o).
 lemma rdeq_inv_lifts_sn: ∀h,o. f_dropable_sn (cdeq h o).
 /2 width=5 by rex_dropable_sn/ qed-.
 
-(* Note: missing in basic_2A1 *)
 lemma rdeq_inv_lifts_dx: ∀h,o. f_dropable_dx (cdeq h o).
 /2 width=5 by rex_dropable_dx/ qed-.
 
-(* Basic_2A1: uses: lleq_inv_lift_le lleq_inv_lift_be lleq_inv_lift_ge *)
 lemma rdeq_inv_lifts_bi: ∀h,o,L1,L2,U. L1 ≛[h, o, U] L2 → ∀b,f. 𝐔⦃f⦄ →
                          ∀K1,K2. ⬇*[b, f] L1 ≘ K1 → ⬇*[b, f] L2 ≘ K2 →
                          ∀T. ⬆*[f] T ≘ U → K1 ≛[h, o, T] K2.
@@ -45,3 +43,10 @@ lemma rdeq_inv_lref_pair_sn: ∀h,o,L1,L2,i. L1 ≛[h, o, #i] L2 → ∀I,K1,V1.
 lemma rdeq_inv_lref_pair_dx: ∀h,o,L1,L2,i. L1 ≛[h, o, #i] L2 → ∀I,K2,V2. ⬇*[i] L2 ≘ K2.ⓑ{I}V2 →
                              ∃∃K1,V1. ⬇*[i] L1 ≘ K1.ⓑ{I}V1 & K1 ≛[h, o, V1] K2 & V1 ≛[h, o] V2.
 /2 width=3 by rex_inv_lref_pair_dx/ qed-.
+
+lemma rdeq_inv_lref_pair_bi (h) (o) (L1) (L2) (i):
+                            L1 ≛[h,o,#i] L2 →
+                            ∀I1,K1,V1. ⬇*[i] L1 ≘ K1.ⓑ{I1}V1 →
+                            ∀I2,K2,V2. ⬇*[i] L2 ≘ K2.ⓑ{I2}V2 →
+                            ∧∧ K1 ≛[h,o,V1] K2 & V1 ≛[h,o] V2 & I1 = I2.
+/2 width=6 by rex_inv_lref_pair_bi/ qed-.