diff -r 4cb70e7e36b9 -r 15e9ed5b28fb src/Pure/ROOT
--- a/src/Pure/ROOT	Thu Nov 08 22:02:07 2018 +0100
+++ b/src/Pure/ROOT	Thu Nov 08 22:29:09 2018 +0100
@@ -1,9 +1,9 @@
 chapter Pure
 
 session Pure =
-  description {*
+  description \<open>
     The Pure logical framework
-  *}
+\<close>
   options [threads = 1, export_theory]
   theories
     Pure (global)