摘要
本文提出了可交换上下文无关文法及其该文法产生的语言——可交换上下文无关语言,证明了正规语言类是可交换上下文无关语言类的一个子集,而可交换上下文无关语言类是上下文无关语言类的一个子集;讨论了可交换上下文无关语言的结构特点,并给出了可交换上下文无关语言的Pumping引理。
The concept of commutative context-free grammar is presented in this paper, L is said to be a commutative context-free language if there is a commutative context-free grammar G such that L=L（G） ; It is proofed that the class language is a proper subclass of context-free language;The structural feature of commutative context-free language is analyzed; The Pumping lemma of commutative context-free language is given.
出处
《计算机科学》
CSCD
北大核心
2007年第7期254-256,共3页
Computer Science
