- revision of ground_2 and basic_2

[helm.git] / matita / matita / contribs / lambdadelta / basic_2 / substitution / lpx_sn_drop.ma

diff --git a/matita/matita/contribs/lambdadelta/basic_2/substitution/lpx_sn_drop.ma b/matita/matita/contribs/lambdadelta/basic_2/substitution/lpx_sn_drop.ma
index 3b7b6ebab57bba9c0cd57db0e54c4cfbf4f818f7..6eb2dd8b2c5880e3c330fc524515c470524d84be 100644 (file)
--- a/matita/matita/contribs/lambdadelta/basic_2/substitution/lpx_sn_drop.ma
+++ b/matita/matita/contribs/lambdadelta/basic_2/substitution/lpx_sn_drop.ma
@@ -87,7 +87,7 @@ qed-.
 fact lpx_sn_dropable_aux: ∀R,L2,K2,s,l,m. ⬇[s, l, m] L2 ≡ K2 → ∀L1. lpx_sn R L1 L2 →
                           l = 0 → ∃∃K1. ⬇[s, 0, m] L1 ≡ K1 & lpx_sn R K1 K2.
 #R #L2 #K2 #s #l #m #H elim H -L2 -K2 -l -m
-[ #l #m #Hm #X #H >(lpx_sn_inv_atom2 … H) -H 
+[ #l #m #Hm #X #H >(lpx_sn_inv_atom2 … H) -H
   /4 width=3 by drop_atom, lpx_sn_atom, ex2_intro/
 | #I #K2 #V2 #X #H elim (lpx_sn_inv_pair2 … H) -H
   #K1 #V1 #HK12 #HV12 #H destruct
@@ -95,8 +95,7 @@ fact lpx_sn_dropable_aux: ∀R,L2,K2,s,l,m. ⬇[s, l, m] L2 ≡ K2 → ∀L1. lp
 | #I #L2 #K2 #V2 #m #_ #IHLK2 #X #H #_ elim (lpx_sn_inv_pair2 … H) -H
   #L1 #V1 #HL12 #HV12 #H destruct
   elim (IHLK2 … HL12) -L2 /3 width=3 by drop_drop, ex2_intro/
-| #I #L2 #K2 #V2 #W2 #l #m #_ #_ #_ #L1 #_
-  <plus_n_Sm #H destruct
+| #I #L2 #K2 #V2 #W2 #l #m #_ #_ #_ #L1 #_ #H elim (ysucc_inv_O_dx … H)
 ]
 qed-.