上下文无关

If (X,a) is a pair of symbols of any context free grammar, then there is at most one generalized precedence relation between X aad a. 在分析速度和占用内存方面,广义优先文法与弱优先文法相似,但前者包含的文法类更广。

If( X, a) is a pair of symbols of any context free grammar, then there is at most one generalized precedence relation between X aad a. 指出基因表达式编程和仅含有单个非终结符的上下文无关文法在描述能力上是等价的。

LFC is different from otherfunctional languages in that LFC uses context free language (CFL) as its basic datatype and the theory of CFRF (Recursive Function defined on Context-Freelanguages) as its theoretical basis. 作为一种函数式语言，LFC 语言具有函数式语言共有的特点，而 LFC 语言与其它函数式语言不同的地方在于其将上下文无关语言(CFL)作为基本的数据类型，其理论基础是上下文无关语言递归函数(CFRF)理论。

This essay summarizes the effects, problems and solutions of Chinese parsing using CTT with a Chinese simple Context Free Grammar (CFG) after a brief introduction of the composition, several characteristics of the Copenhagen Tree Tracer (CTT) program. 本文简要介绍了自然语言处理的图形接口软件CTT(Copenhagen Tree Tracer),并介绍了利用它在简单的CFG形式化体系下做汉语自动句法分析的状况、存在问题、解决办法。

On the basis of the formalizable characteristic of music rhythm, a probabilistic context free grammar (PCFG) system was defined to describe the relatively independent music rhythm elements. 基于音乐节奏本身具有可被形式化的特性，定义了一个概率上下文无关文法(PCFG)系统来描述相对独立的音乐节奏元素。

Metaobject parsing is a formalized method, which is used for system comprehension of the procedure-oriented legacy software.The method is based on object-oriented context free grammar. 元对象分析法是理解面向过程遗产软件系统的一种形式化方法，这种方法以面向对象的上下文无关文法为基础。