update in ground_2

[helm.git] / matita / matita / contribs / lambdadelta / ground_2 / lib / relations.ma

diff --git a/matita/matita/contribs/lambdadelta/ground_2/lib/relations.ma b/matita/matita/contribs/lambdadelta/ground_2/lib/relations.ma
index 86be386408dbf8856a3c91e8a9956f7311bbee75..fa8bae34356880363acc0a6369876121b7bbe6d9 100644 (file)
--- a/matita/matita/contribs/lambdadelta/ground_2/lib/relations.ma
+++ b/matita/matita/contribs/lambdadelta/ground_2/lib/relations.ma
@@ -13,10 +13,13 @@
 (**************************************************************************)
 
 include "basics/relations.ma".
-include "ground_2/xoa/xoa_props.ma".
+include "ground_2/lib/logic.ma".
 
 (* GENERIC RELATIONS ********************************************************)
 
+definition replace_2 (A) (B): relation3 (relation2 A B) (relation A) (relation B) ≝
+                              λR,Sa,Sb. ∀a1,b1. R a1 b1 → ∀a2. Sa a1 a2 → ∀b2. Sb b1 b2 → R a2 b2.
+
 (* Inclusion ****************************************************************)
 
 definition subR2 (S1) (S2): relation (relation2 S1 S2) ≝