X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fmatita%2Fnlibrary%2Falgebra%2Fmagmas.ma;h=4fac05b51c6e2926fdaa85f21e9edc8db03561a0;hb=6003ba0e4600778c6055ed5ea5cb6c1fba3abe32;hp=7283cbc58f95d733587a3b15cfe9b5b01a8de5e6;hpb=72aa8b2087285826b14fc39a389632f0317c51b6;p=helm.git

diff --git a/helm/software/matita/nlibrary/algebra/magmas.ma b/helm/software/matita/nlibrary/algebra/magmas.ma
index 7283cbc58..4fac05b51 100644
--- a/helm/software/matita/nlibrary/algebra/magmas.ma
+++ b/helm/software/matita/nlibrary/algebra/magmas.ma
@@ -47,6 +47,10 @@ ndefinition mmcarr ≝
  λA,B.λf: pre_magma_morphism A B. match f with [ mk_pre_magma_morphism f _ ⇒ f ].
 ncoercion mmcarr: ∀A,B.∀M: pre_magma_morphism A B. A → B ≝ mmcarr
  on _M: pre_magma_morphism ? ? to ∀_.?.
+ndefinition mmprop ≝
+ λA,B,M.
+  match M return λM:pre_magma_morphism A B.∀x,y. M (op ? x y) = op ? (M x) (M y) with
+   [ mk_pre_magma_morphism _ p ⇒ p ].
 
 nrecord magma_morphism (A) (B) (Ma: magma A) (Mb: magma B) : Type ≝
  { mmmcarr: pre_magma_morphism A B;
@@ -81,5 +85,8 @@ ndefinition mm_image:
      [ napply (op ? x0 y0) 
      | napply (conj ????)
         [ napply (op_closed ??????); nassumption
-        | nelim daemon ]##]
+        | (* nrewrite < Hx1; DOES NOT WORK *)
+          napply (eq_rect ?? (λ_.?) ?? Hx1);
+          napply (eq_rect ?? (λ_.?) ?? Hy1);
+          napply (mmprop ?? f ??)]##]
 nqed.
\ No newline at end of file