diff -r c8a2755bf220 -r ff784d5a5bfb src/HOL/Quickcheck_Examples/Quickcheck_Narrowing_Examples.thy
--- a/src/HOL/Quickcheck_Examples/Quickcheck_Narrowing_Examples.thy	Sat Jan 05 17:00:43 2019 +0100
+++ b/src/HOL/Quickcheck_Examples/Quickcheck_Narrowing_Examples.thy	Sat Jan 05 17:24:33 2019 +0100
@@ -221,7 +221,7 @@
 
 declare is_ord.simps(1)[code] is_ord_mkt[code]
 
-subsubsection \<open>Invalid Lemma due to typo in @{const l_bal}\<close>
+subsubsection \<open>Invalid Lemma due to typo in \<^const>\<open>l_bal\<close>\<close>
 
 lemma is_ord_l_bal:
  "\<lbrakk> is_ord(MKT (x :: nat) l r h); height l = height r + 2 \<rbrakk> \<Longrightarrow> is_ord(l_bal(x,l,r))"