X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fmatita%2Flibrary%2Fnat%2Fplus.ma;h=1c145dd6141cea519fd99f7c681a179159a72346;hb=3a12950125e7a4a792546aacea40505f3cecae89;hp=e8750d0cba0f41a0995a23524a8d6f887a83204e;hpb=9c8bb7e7c2548d2f37e5387cdce45df2b8fc9b43;p=helm.git

diff --git a/helm/matita/library/nat/plus.ma b/helm/matita/library/nat/plus.ma
index e8750d0cb..1c145dd61 100644
--- a/helm/matita/library/nat/plus.ma
+++ b/helm/matita/library/nat/plus.ma
@@ -21,13 +21,16 @@ let rec plus n m \def
  [ O \Rightarrow m
  | (S p) \Rightarrow S (plus p m) ].
 
-theorem plus_n_O: \forall n:nat. eq nat n (plus n O).
+(*CSC: the URI must disappear: there is a bug now *)
+interpretation "natural plus" 'plus x y = (cic:/matita/nat/plus/plus.con x y).
+
+theorem plus_n_O: \forall n:nat. n = n+O.
 intros.elim n.
 simplify.reflexivity.
 simplify.apply eq_f.assumption.
 qed.
 
-theorem plus_n_Sm : \forall n,m:nat. eq nat (S (plus n  m)) (plus n (S m)).
+theorem plus_n_Sm : \forall n,m:nat. S (n+m) = n+(S m).
 intros.elim n.
 simplify.reflexivity.
 simplify.apply eq_f.assumption.
@@ -38,7 +41,7 @@ and functions/symmetric; functions symmetric is not in
 functions.moo why?
 theorem symmetric_plus: symmetric nat plus. *)
 
-theorem sym_plus: \forall n,m:nat. eq nat (plus n m) (plus m n).
+theorem sym_plus: \forall n,m:nat. n+m = m+n.
 intros.elim n.
 simplify.apply plus_n_O.
 simplify.rewrite > H.apply plus_n_Sm.
@@ -50,19 +53,19 @@ simplify.reflexivity.
 simplify.apply eq_f.assumption.
 qed.
 
-theorem assoc_plus : \forall n,m,p:nat. eq nat (plus (plus n m) p) (plus n (plus m p))
+theorem assoc_plus : \forall n,m,p:nat. (n+m)+p = n+(m+p)
 \def associative_plus.
 
-theorem injective_plus_r: \forall n:nat.injective nat nat (\lambda m.plus n m).
+theorem injective_plus_r: \forall n:nat.injective nat nat (\lambda m.n+m).
 intro.simplify.intros 2.elim n.
 exact H.
 apply H.apply inj_S.apply H1.
 qed.
 
-theorem inj_plus_r: \forall p,n,m:nat.eq nat (plus p n) (plus p m) \to (eq nat n m)
+theorem inj_plus_r: \forall p,n,m:nat. p+n = p+m \to n=m
 \def injective_plus_r.
 
-theorem injective_plus_l: \forall m:nat.injective nat nat (\lambda n.plus n m).
+theorem injective_plus_l: \forall m:nat.injective nat nat (\lambda n.n+m).
 intro.simplify.intros.
 (* qui vorrei applicare injective_plus_r *)
 apply inj_plus_r m.
@@ -71,5 +74,5 @@ rewrite < sym_plus y.
 assumption.
 qed.
 
-theorem inj_plus_l: \forall p,n,m:nat.eq nat (plus n p) (plus m p) \to (eq nat n m)
+theorem inj_plus_l: \forall p,n,m:nat. n+p = m+p \to n=m
 \def injective_plus_l.