--- a/src/Doc/Demo_Easychair/ROOT	Sat Nov 05 14:53:29 2022 +0100
+++ b/src/Doc/Demo_Easychair/ROOT	Sat Nov 05 16:24:59 2022 +0100
@@ -1,7 +1,7 @@
-chapter Doc
+chapter Doc  (*Isabelle documentation*)
 
 session Demo_Easychair (doc) = HOL +
-  options [document_variants = "demo_easychair"]
+  options [document_variants = "demo_easychair"]  (*Isabelle documentation*)
   theories
     Document
   document_files (in "$ISABELLE_EASYCHAIR_HOME")