diff --git a/grammar/LexerCircom.g4 b/grammar/LexerCircom.g4
index c532963..4bfeeb4 100644
--- a/grammar/LexerCircom.g4
+++ b/grammar/LexerCircom.g4
@@ -59,8 +59,10 @@ RB: ']' ;
 LC: '{' ;
 RC: '}' ;
 
+COLON: ':' ;
 SEMICOLON: ';' ;
 
+DOT: '.' ;
 COMMA: ',' ;
 
 ASSIGNMENT: '=' ;
@@ -75,6 +77,10 @@ RIGHT_ASSIGNMENT: '-->' | '==>' ;
 
 CONSTRAINT_EQ: '===' ;
 
+QUESTION_MARK: '?' ;
+
+UNDERSCORE: '_' ;
+
 NOT: '!' ;
 BNOT: '~' ;