--- a/src/Doc/System/Sessions.thy Mon Dec 09 12:27:18 2013 +0100
+++ b/src/Doc/System/Sessions.thy Mon Dec 09 20:16:12 2013 +0100
@@ -356,7 +356,7 @@
\medskip Option @{verbatim "-s"} enables \emph{system mode}, which
means that resulting heap images and log files are stored in
- @{verbatim "$ISABELLE_HOME/heaps"} instead of the default location
+ @{file_unchecked "$ISABELLE_HOME/heaps"} instead of the default location
@{setting ISABELLE_OUTPUT} (which is normally in @{setting
ISABELLE_HOME_USER}, i.e.\ the user's home directory).