avoid using Int.succ or Int.pred in proofs

--- a/src/HOL/Word/Word.thy	Fri Feb 24 16:53:59 2012 +0100
+++ b/src/HOL/Word/Word.thy	Fri Feb 24 16:55:29 2012 +0100
@@ -1598,7 +1598,7 @@
   apply (unfold word_succ_def)
   apply clarify
   apply (simp add: to_bl_of_bin)
-  apply (simp add: to_bl_def rbl_succ Int.succ_def)
+  apply (simp add: to_bl_def rbl_succ)
   done
 
 lemma word_pred_rbl:
@@ -1606,7 +1606,7 @@
   apply (unfold word_pred_def)
   apply clarify
   apply (simp add: to_bl_of_bin)
-  apply (simp add: to_bl_def rbl_pred Int.pred_def)
+  apply (simp add: to_bl_def rbl_pred)
   done
 
 lemma word_add_rbl: