diff -r a78ecc7341e3 -r 63f0b2601792 src/ZF/equalities.ML
--- a/src/ZF/equalities.ML	Thu Feb 26 15:45:33 1998 +0100
+++ b/src/ZF/equalities.ML	Fri Feb 27 11:06:28 1998 +0100
@@ -476,6 +476,16 @@
 by (Blast_tac 1);
 qed "vimage_Int_subset";
 
+goalw thy [function_def]
+    "!!f. function(f) ==> f-``(A Int B) = (f-``A)  Int  (f-``B)";
+by (Blast_tac 1);
+qed "function_vimage_Int";
+
+goalw thy [function_def]
+    "!!f. function(f) ==> f-``(A-B) = (f-``A) - (f-``B)";
+by (Blast_tac 1);
+qed "function_vimage_Diff";
+
 goal ZF.thy "(r Int A*A)-``B <= (r-``B) Int A";
 by (Blast_tac 1);
 qed "vimage_Int_square_subset";