diff --git a/test.Mod b/test.Mod
index 0c5d897..8d49b34 100644
--- a/test.Mod
+++ b/test.Mod
@@ -1,6 +1,6 @@
 MODULE test;
 
-IMPORT Days;
+IMPORT Days, Out;
 
 VAR today, yesterday, tomorrow: Days.Day;
 
@@ -8,6 +8,15 @@ BEGIN
   today := Days.mon; (*init*)
 
   yesterday := Days.Prev(today);
+  IF yesterday = Days.sun
+  THEN
+    Out.String("it works!"); Out.Ln
+  END;
   tomorrow := Days.Next(today);
 
+  IF tomorrow = Days.tue
+  THEN
+    Out.String("it works!"); Out.Ln
+  END;
+
 END test.