This file comprises of two entries, which are aliases and the user specifications in Extended Backus-Naur form.

该文件由两个条目组成，分别是别名和Extended Backus - naur格式的用户规范。

The grammars for complex languages are commonly described using BNF (Backus-Naur Form) notation or its close relative, EBNF (Extended BNF).

复杂语言的语法通常都是使用 BNF（巴科斯-诺尔范式，Backus-Naur Form）表示法或者其“近亲”― EBNF（扩展的 BNF）描述的。

A design model of NC code complier based on ANother Tool for Language Recognition (ANTLR) was presented, which adopted the Extended Backus Naur Form (EBNF) to define the NC program syntax rule.

采用了扩展的巴科斯范式(EBNF)定义NC程序语法规则，提出了一种基于语言识别工具(ANTLR)的NC代码编译器的设计模型。