diff -r 760e21900b01 -r 28e788ca2c5d src/Doc/Isar_Ref/HOL_Specific.thy
--- a/src/Doc/Isar_Ref/HOL_Specific.thy	Thu Oct 22 21:16:27 2015 +0200
+++ b/src/Doc/Isar_Ref/HOL_Specific.thy	Thu Oct 22 21:16:49 2015 +0200
@@ -2469,9 +2469,9 @@
   hierarchy. Omitting the file specification denotes standard output.
 
   Serializers take an optional list of arguments in parentheses. For
-  \<^emph>\<open>Haskell\<close> a module name prefix may be given using the ``\<open>root:\<close>'' argument; ``\<open>string_classes\<close>'' adds a ``@{verbatim
-  "deriving (Read, Show)"}'' clause to each appropriate datatype
-  declaration.
+  \<^emph>\<open>Haskell\<close> a module name prefix may be given using the ``\<open>root:\<close>'' argument;
+  ``\<open>string_classes\<close>'' adds a ``\<^verbatim>\<open>deriving (Read, Show)\<close>'' clause to each
+  appropriate datatype declaration.
 
   \<^descr> @{attribute (HOL) code} declare code equations for code generation.
   Variant \<open>code equation\<close> declares a conventional equation as code