new_contents: # coding: utf-8
  __author__ = 'AprocySanae'
  __date__ = '15/3/15'
  
  
  def name_evaluate(self, env, value_type):
      result = env.get(self.value)
      if result is None:
          raise SyntaxError("name '{}' is not defined".format(self.value))
      return result
  
  
  def init_eval():
      r = dict()
      r['(number)'] = name_evaluate
      return r
subject: add string operand