diff --git a/psGrammar/demos/demoDynamic.jsgf b/psGrammar/demos/demoDynamic.jsgf
index 9638db156fa032595f1c31faaea928c8ee8c2fa0..fbd733661cf880b821d242e8f4b8ece7fb3e7b26 100644
--- a/psGrammar/demos/demoDynamic.jsgf
+++ b/psGrammar/demos/demoDynamic.jsgf
@@ -27,4 +27,5 @@ public <command> = [<robot>] ( <save> | <wave> | <who> | <goTo> | <followMe> | <
 <grasp> = ((grasp | give ) [me] ( an | the ) object);
 
 <trash> = ([please] ((take out the trash) | (take out the garbage)));
-<search> = ([please] search for [a] [waving] person);
\ No newline at end of file
+<search> = ([please] search for [a] [waving] person);
+<difference> = (spot the difference)
\ No newline at end of file