X-Git-Url: http://matita.cs.unibo.it/gitweb/?p=helm.git;a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fstatic_2%2Fstatic%2Frdeq_drops.ma;h=825ed84d94b644a26ba529e6551beae43943a821;hp=3a44480798ba19be67885cb579781a6f0f564db6;hb=b98ec1a1a37602eca524dc5487c357a200bbb5b6;hpb=eeeaecfafd5ddffa54a41356104fbc60369e5d73

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 3a4448079..825ed84d9 100644
--- a/matita/matita/contribs/lambdadelta/static_2/static/rdeq_drops.ma
+++ b/matita/matita/contribs/lambdadelta/static_2/static/rdeq_drops.ma
@@ -43,3 +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-.