original_string: public function rule_false($a)
      {
          // Changes PHP false to 0
          $a = strtolower($a);
  
          $vals = array('false', 'f', 0, 'no', 'n');
  
          if (!in_array($a, $vals)) {
              return $this->fail('Must be false');
          }
      }
code: public function rule_false($a)
      {
          // Changes PHP false to 0
          $a = strtolower($a);
  
          $vals = array('false', 'f', 0, 'no', 'n');
  
          if (!in_array($a, $vals)) {
              return $this->fail('Must be false');
          }
      }
code_tokens: public function rule_false ( $ a ) { // Changes PHP false to 0 $ a = strtolower ( $ a ) ; $ vals = array ( 'false' , 'f' , 0 , 'no' , 'n' ) ; if ( ! in_array ( $ a , $ vals ) ) { return $ this -> fail ( 'Must be false' ) ; } }
docstring: Validate for false|f|0|no|n.
  
  Normalizes to lower case
  
  Useful for 'if' rules
docstring_tokens: Validate for false|f|0|no|n .