diff --git a/gamarjoba.lean b/gamarjoba.lean
index 5e97341..51535c8 100644
--- a/gamarjoba.lean
+++ b/gamarjoba.lean
@@ -2,6 +2,7 @@ import system.io
 
 open io
 
+#check (++)
 def greet (s : string) : io unit :=
     put_str $ "Hello, " ++ s ++ "!\n"