X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fground_2%2Flib%2Ffunctions.ma;h=739fb8d4f47cbc12fe91ddcf06b9bfd694b2f4a0;hb=1fd63df4c77f5c24024769432ea8492748b4ac79;hp=4977504b9e988a440fa7d5fb0de75a3e0b247a66;hpb=2976c347e18717e691825ebdf73a5ce941c57d1b;p=helm.git

diff --git a/matita/matita/contribs/lambdadelta/ground_2/lib/functions.ma b/matita/matita/contribs/lambdadelta/ground_2/lib/functions.ma
index 4977504b9..739fb8d4f 100644
--- a/matita/matita/contribs/lambdadelta/ground_2/lib/functions.ma
+++ b/matita/matita/contribs/lambdadelta/ground_2/lib/functions.ma
@@ -20,10 +20,15 @@ definition left_identity (A) (f): predicate A ≝ λi. ∀a:A. a = f i a.
 
 definition right_identity (A) (f): predicate A ≝ λi. ∀a:A. a = f a i.
 
-definition compatible_2 (A) (B): relation3 … (relation A) (relation B) ≝
-                                 λf,Sa,Sb.
-                                 ∀a1,a2. Sa a1 a2 → Sb (f a1) (f a2).
+definition compatible_2 (A) (B):
+                        relation3 … (relation A) (relation B) ≝
+                        λf,Sa,Sb.
+                        ∀a1,a2. Sa a1 a2 → Sb (f a1) (f a2).
 
-definition compatible_3 (A) (B) (C): relation4 … (relation A) (relation B) (relation C) ≝
-                                     λf,Sa,Sb,Sc.
-                                     ∀a1,a2. Sa a1 a2 → ∀b1,b2. Sb b1 b2 → Sc (f a1 b1) (f a2 b2).
+definition compatible_3 (A) (B) (C):
+                        relation4 … (relation A) (relation B) (relation C) ≝
+                        λf,Sa,Sb,Sc.
+                        ∀a1,a2. Sa a1 a2 → ∀b1,b2. Sb b1 b2 → Sc (f a1 b1) (f a2 b2).
+
+definition annulment_2 (A) (f): predicate A ≝
+                       λi:A. ∀a1,a2. i = f a1 a2 → ∧∧ i = a1 & i = a2.