X-Git-Url: http://matita.cs.unibo.it/gitweb/?p=helm.git;a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fground_2%2Fynat%2Fynat_lt.ma;h=ab9cf4565cc365d28ff3d8d94b3a8b2359e91c02;hp=ab87ca2788bb1f747103094451963e85e03206e2;hb=87f57ddc367303c33e19c83cd8989cd561f3185b;hpb=d777d94825ce0127beefaec44b7808e9c1916340

diff --git a/matita/matita/contribs/lambdadelta/ground_2/ynat/ynat_lt.ma b/matita/matita/contribs/lambdadelta/ground_2/ynat/ynat_lt.ma
index ab87ca278..ab9cf4565 100644
--- a/matita/matita/contribs/lambdadelta/ground_2/ynat/ynat_lt.ma
+++ b/matita/matita/contribs/lambdadelta/ground_2/ynat/ynat_lt.ma
@@ -199,6 +199,10 @@ lemma yle_ylt_trans: ∀x:ynat. ∀y:ynat. ∀z:ynat. y < z → x ≤ y → x <
 ]
 qed-.
 
+lemma le_ylt_trans (x) (y) (z): x ≤ y → yinj y < z → yinj x < z.  
+/3 width=3 by yle_ylt_trans, yle_inj/
+qed-.
+
 lemma yle_inv_succ1_lt: ∀x,y:ynat. ↑x ≤ y → 0 < y ∧ x ≤ ↓y.
 #x #y #H elim (yle_inv_succ1 … H) -H /3 width=1 by ylt_O1, conj/
 qed-.
@@ -219,6 +223,10 @@ theorem ylt_trans: Transitive … ylt.
 ]
 qed-.
 
+lemma lt_ylt_trans (x) (y) (z): x < y → yinj y < z → yinj x < z.  
+/3 width=3 by ylt_trans, ylt_inj/
+qed-.
+
 (* Elimination principles ***************************************************)
 
 fact ynat_ind_lt_le_aux: ∀R:predicate ynat.