421     def __eq__(self, rhs):  argument
423         return self.value == rhs.value
464     def __eq__(self, rhs):  argument
466         return self.value == rhs.value
529     def __init__(self, lhs, rhs):  argument
532         self.rhs = rhs
536         return '(' + repr(self.lhs) + ' + ' + repr(self.rhs) + ')'
542         rhs = self.rhs.eval(env)
543         if isinstance(lhs, List) and isinstance(rhs, List):
544             return List(itertools.chain(lhs, rhs))
545         if isinstance(lhs, String) and isinstance(rhs, String):
546             return String(lhs + rhs)
547         if isinstance(lhs, Integer) and isinstance(rhs, Integer):
548             return Integer(int(lhs) + int(rhs))