diff --git a/relational/parser.py b/relational/parser.py
index c2b386c..7f0b682 100644
--- a/relational/parser.py
+++ b/relational/parser.py
@@ -29,10 +29,6 @@ from dataclasses import dataclass
 
 from relational import rtypes
 
-RELATION = 0
-UNARY = 1
-BINARY = 2
-
 PRODUCT = '*'
 DIFFERENCE = '-'
 UNION = '∪'