--- a/src/HOL/Decision_Procs/Algebra_Aux.thy Wed Jan 10 12:35:03 2018 +0100
+++ b/src/HOL/Decision_Procs/Algebra_Aux.thy Wed Jan 10 13:35:56 2018 +0100
@@ -234,7 +234,7 @@
by (induct n) (simp_all add: m_ac)
definition cring_class_ops :: "'a::comm_ring_1 ring"
- where "cring_class_ops \<equiv> \<lparr>carrier = UNIV, mult = op *, one = 1, zero = 0, add = op +\<rparr>"
+ where "cring_class_ops \<equiv> \<lparr>carrier = UNIV, mult = op *, one = 1, zero = 0, add = (op +)\<rparr>"
lemma cring_class: "cring cring_class_ops"
apply unfold_locales