X-Git-Url: http://matita.cs.unibo.it/gitweb/?p=helm.git;a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fstatic_2%2Fstatic%2Ffsle_drops.ma;h=542d8b10e584eac58b886d0e32093de480ccaada;hp=8375d521a07dca47cf7f90008de8294836d98d10;hb=50a9ed8c6207145fccf59e6a5dbbff935cd2c6d7;hpb=d71e53021b0c17e1a00c2d623e7139c6d18069d5

diff --git a/matita/matita/contribs/lambdadelta/static_2/static/fsle_drops.ma b/matita/matita/contribs/lambdadelta/static_2/static/fsle_drops.ma
index 8375d521a..542d8b10e 100644
--- a/matita/matita/contribs/lambdadelta/static_2/static/fsle_drops.ma
+++ b/matita/matita/contribs/lambdadelta/static_2/static/fsle_drops.ma
@@ -29,6 +29,17 @@ lapply (frees_lifts_SO (Ⓣ) (L1.ⓧ) … HTU1 … Hf)
 @(ex4_4_intro … Hf Hg) /2 width=4 by lveq_void_sn/ (**) (* explict constructor *)
 qed-.
 
+lemma fsle_lifts_dx (L1) (L2):
+                    |L1| ≤ |L2| → ∀T2,U2. ⬆*[1]T2 ≘ U2 →
+                    ∀T1. ⦃L1,T1⦄ ⊆ ⦃L2,T2⦄ → ⦃L1,T1⦄ ⊆ ⦃L2.ⓧ,U2⦄.
+#L1 #L2 #HL21 #T2 #U2 #HTU2 #T1
+* #n #m #f #g #Hf #Hg #H2L #Hfg
+lapply (lveq_length_fwd_sn … H2L ?) // -HL21 #H destruct
+lapply (frees_lifts_SO (Ⓣ) (L2.ⓧ) … HTU2 … Hg)
+[ /3 width=4 by drops_refl, drops_drop/ ] -T2 #Hg
+@(ex4_4_intro … Hf Hg) /2 width=4 by lveq_void_dx/ (**) (* explict constructor *)
+qed-.
+
 lemma fsle_lifts_SO_sn: ∀K1,K2. |K1| = |K2| → ∀V1,V2. ⦃K1, V1⦄ ⊆ ⦃K2, V2⦄ →
                         ∀W1. ⬆*[1] V1 ≘ W1 → ∀I1,I2. ⦃K1.ⓘ{I1}, W1⦄ ⊆ ⦃K2.ⓑ{I2}V2, #O⦄.
 #K1 #K2 #HK #V1 #V2