--- a/thys/ROOT	Wed Aug 15 13:48:57 2018 +0100
+++ b/thys/ROOT	Thu Aug 16 01:12:00 2018 +0100
@@ -5,7 +5,7 @@
         "Lexer"
         (*"LexerExt"*)
         "Simplifying"
-        (*"Sulzmann"*) 
+        "Sulzmann" 
         "Positions"
 	(*"PositionsExt"*)
         "Exercises"