diff --git a/src/types/mod.rs b/src/types/mod.rs
index b71935f..2fdf4d8 100644
--- a/src/types/mod.rs
+++ b/src/types/mod.rs
@@ -8,3 +8,7 @@ pub mod number;
 
 pub type Boolean = bool;
 pub type Character = char;
+
+pub trait Value { }
+impl Value for Boolean { }
+impl Value for Character { }