--- a/src/HOL/Algebra/IntRing.thy Sat Jan 06 09:39:57 2018 +0100
+++ b/src/HOL/Algebra/IntRing.thy Sat Jan 06 10:08:11 2018 +0100
@@ -23,7 +23,7 @@
subsection \<open>\<open>\<Z>\<close>: The Set of Integers as Algebraic Structure\<close>
abbreviation int_ring :: "int ring" ("\<Z>")
- where "int_ring \<equiv> \<lparr>carrier = UNIV, mult = op *, one = 1, zero = 0, add = op +\<rparr>"
+ where "int_ring \<equiv> \<lparr>carrier = UNIV, mult = op *, one = 1, zero = 0, add = (op +)\<rparr>"
lemma int_Zcarr [intro!, simp]: "k \<in> carrier \<Z>"
by simp