有一个魔王总是使用自己的一种非常精炼而抽象的语言讲话，没有人能听懂。但他的语言是可以逐步解释成人能懂的语言的，因为他的语言是由以下两种形式的规则由人的语言逐步抽象上去的：

(1) α→β1β2 …… βm

(2) (θδ1δ2 …… δn)→ θδnθδn-1 …… θδ1 θ

-A devil always use a very refined and abstract language speech, no one can understand. But his language is gradually explain adult can understand the language, because his language is human language gradually by the rules of the following two forms of abstraction up of: (1) α → β1β2-...... βm (2) (θδ1δ2 ...... δn) → θδnθδn-1 ...... θδ1 θ