added lemma
authornipkow
Fri, 06 Mar 2009 22:06:33 +0100
changeset 30323 6a02238da8e9
parent 30322 90e309d20d58
child 30324 9afd9a9d0812
child 30370 79a7491ac1fd
added lemma
src/HOL/IntDiv.thy
--- a/src/HOL/IntDiv.thy	Fri Mar 06 21:57:56 2009 +0100
+++ b/src/HOL/IntDiv.thy	Fri Mar 06 22:06:33 2009 +0100
@@ -1025,9 +1025,12 @@
 apply (auto simp add: div_eq_minus1)
 done
 
-lemma div_nonneg_neg_le0: "[| (0::int) \<le> a;  b < 0 |] ==> a div b \<le> 0"
+lemma div_nonneg_neg_le0: "[| (0::int) \<le> a; b < 0 |] ==> a div b \<le> 0"
 by (drule zdiv_mono1_neg, auto)
 
+lemma div_nonpos_pos_le0: "[| (a::int) \<le> 0; b > 0 |] ==> a div b \<le> 0"
+by (drule zdiv_mono1, auto)
+
 lemma pos_imp_zdiv_nonneg_iff: "(0::int) < b ==> (0 \<le> a div b) = (0 \<le> a)"
 apply auto
 apply (drule_tac [2] zdiv_mono1)