diff -r fb4fe9f8c3cd -r d64593bb95d3 Arith.ML
--- a/Arith.ML	Wed May 25 12:43:50 1994 +0200
+++ b/Arith.ML	Wed May 25 13:03:19 1994 +0200
@@ -21,12 +21,14 @@
 
 val diff_0 = diff_def RS def_nat_rec_0;
 
-val diff_0_eq_0 = prove_goalw Arith.thy [diff_def] "0 - n = 0"
+val diff_0_eq_0 = prove_goalw Arith.thy [diff_def, pred_def]
+    "0 - n = 0"
  (fn _ => [nat_ind_tac "n" 1,  ALLGOALS(asm_simp_tac nat_ss)]);
 
 (*Must simplify BEFORE the induction!!  (Else we get a critical pair)
   Suc(m) - Suc(n)   rewrites to   pred(Suc(m) - n)  *)
-val diff_Suc_Suc = prove_goalw Arith.thy [diff_def] "Suc(m) - Suc(n) = m - n"
+val diff_Suc_Suc = prove_goalw Arith.thy [diff_def, pred_def]
+    "Suc(m) - Suc(n) = m - n"
  (fn _ =>
   [simp_tac nat_ss 1, nat_ind_tac "n" 1, ALLGOALS(asm_simp_tac nat_ss)]);