--- a/src/HOL/Algebra/QuotRing.thy Sun Mar 21 15:57:40 2010 +0100
+++ b/src/HOL/Algebra/QuotRing.thy Sun Mar 21 16:51:37 2010 +0100
@@ -14,7 +14,7 @@
definition
rcoset_mult :: "[('a, _) ring_scheme, 'a set, 'a set, 'a set] \<Rightarrow> 'a set"
("[mod _:] _ \<Otimes>\<index> _" [81,81,81] 80)
- where "rcoset_mult R I A B \<equiv> \<Union>a\<in>A. \<Union>b\<in>B. I +>\<^bsub>R\<^esub> (a \<otimes>\<^bsub>R\<^esub> b)"
+ where "rcoset_mult R I A B = (\<Union>a\<in>A. \<Union>b\<in>B. I +>\<^bsub>R\<^esub> (a \<otimes>\<^bsub>R\<^esub> b))"
text {* @{const "rcoset_mult"} fulfils the properties required by
@@ -91,7 +91,7 @@
definition
FactRing :: "[('a,'b) ring_scheme, 'a set] \<Rightarrow> ('a set) ring" (infixl "Quot" 65)
- where "FactRing R I \<equiv>
+ where "FactRing R I =
\<lparr>carrier = a_rcosets\<^bsub>R\<^esub> I, mult = rcoset_mult R I, one = (I +>\<^bsub>R\<^esub> \<one>\<^bsub>R\<^esub>), zero = I, add = set_add R\<rparr>"