diff --git a/lexer/lexer.go b/lexer/lexer.go
index e14172b..682bc04 100644
--- a/lexer/lexer.go
+++ b/lexer/lexer.go
@@ -97,16 +97,16 @@ func (tok Token) EOF () bool {
 
 func (tok Token) Is (kinds ...TokenKind) bool {
 	for _, kind := range kinds {
-		if tok.Kind != kind { return false }
+		if tok.Kind == kind { return true }
 	}
-	return true
+	return false
 }
 
 func (tok Token) ValueIs (values ...string) bool {
 	for _, value := range values {
-		if tok.Value != value { return false }
+		if tok.Value == value { return true }
 	}
-	return true
+	return false
 }
 
 type Lexer interface {