diff --git a/src/Math.php b/src/Math.php
index ec7f736..34c5532 100644
--- a/src/Math.php
+++ b/src/Math.php
@@ -140,7 +140,12 @@ protected function parseOperator(TerminalExpression $expression, Stack $output,
     }
 
     protected function tokenize($string) {
-        $parts = preg_split('(([0-9]*\.?[0-9]+|\+|-|\(|\)|\*|%|\/|:|\?|==|<=|>=|<|>|!=|&&|\|\|)|\s+)', $string, null, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE);
+        $parts = preg_split(
+            '(([0-9]*\.?[0-9]+|\+|-|\(|\)|\*|%|\/|:|\?|==|<=|>=|<|>|!=|&&|\|\|)|\s+)',
+            $string,
+            null,
+            PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE
+        );
         $parts = array_map('trim', $parts);
         return $parts;
     }