X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fground_2%2Fynat%2Fynat_plus.ma;h=16a933acf7472d41f4d6269153c6333f919a48ef;hb=5102e7f780e83c7fef1d3826f81dfd37ee4028bc;hp=e710032b0391c140715390448a1bd7505b873f4b;hpb=174ee1889b5c91ef5339c718d7657ed0e5da21e8;p=helm.git

diff --git a/matita/matita/contribs/lambdadelta/ground_2/ynat/ynat_plus.ma b/matita/matita/contribs/lambdadelta/ground_2/ynat/ynat_plus.ma
index e710032b0..16a933acf 100644
--- a/matita/matita/contribs/lambdadelta/ground_2/ynat/ynat_plus.ma
+++ b/matita/matita/contribs/lambdadelta/ground_2/ynat/ynat_plus.ma
@@ -93,12 +93,12 @@ qed.
 
 (* Inversion lemmas on successor *********************************************)
 
-lemma yplus_inv_succ_lt_dx: ∀x,y,z. 0 < y → x + y = ⫯z → x + ⫰y = z.
+lemma yplus_inv_succ_lt_dx: ∀x,y,z:ynat. 0 < y → x + y = ⫯z → x + ⫰y = z.
 #x #y #z #H <(ylt_inv_O1 y) // >yplus_succ2
 /2 width=1 by ysucc_inv_inj/
 qed-.
 
-lemma yplus_inv_succ_lt_sn: ∀x,y,z. 0 < x → x + y = ⫯z → ⫰x + y = z.
+lemma yplus_inv_succ_lt_sn: ∀x,y,z:ynat. 0 < x → x + y = ⫯z → ⫰x + y = z.
 #x #y #z #H <(ylt_inv_O1 x) // >yplus_succ1
 /2 width=1 by ysucc_inv_inj/