anchor.diff:      ;
   
   error_logging_clause
  -    : LOG ERRORS error_logging_into_part? expression_wrapper? error_logging_reject_part?
  +    : LOG ERRORS error_logging_into_part? expression? error_logging_reject_part?
       ;
   
   error_logging_into_part
  
positive.code:     ;
  
  additive_expression
      : multiply_expression (('+' | '-') multiply_expression)*
      ;
  
  multiply_expression
      : datetime_expression (('*' | '/') datetime_expression)*
      ;
  
  datetime_expression
  
negative.code:     ;
  
  return_statement
      : RETURN condition?
      ;
  
  function_call
  