两种具有简单上下文检查机制的上下文无关重写系统的比较
Comparison of Two Context-Free Rewriting Systems with Simple Context-Checking Mechanisms
摘要：
本文解决了一个公开的问题，非擦除上下文无关重写系统的生成能力，使用一个简单的机制，检查上下文的依赖关系，在文献中称为半条件文法的程度（1，1）。在这些语法中，两个非终结符被附加到每个上下文无关产生式，并且如果两个附加符号之一出现在当前句子形式中，而另一个不出现，则这样的产生式是适用的。具体地说，本文证明了由（1，1）度半条件文法生成的语言族与随机上下文语言族是一致的。此外，还证明了Mayer证明的有擦除产生式的随机上下文文法的范式对无擦除产生式的随机上下文文法也成立.它还讨论了文献中使用的直接推导步骤的关系的两种可能的定义。
英文摘要：
This paper solves an open problem concerning the generative power of nonerasing context-free rewriting systems using a simple mechanism for checking for context dependencies, in the literature known as semi-conditional grammars of degree (1,1). In these grammars, two nonterminal symbols are attached to each context-free production, and such a production is applicable if one of the two attached symbols occurs in the current sentential form, while the other does not. Specifically, this paper demonstrates that the family of languages generated by semi-conditional grammars of degree (1,1) coincides with the family of random context languages. In addition, it shows that the normal form proved by Mayer for random context grammars with erasing productions holds for random context grammars without erasing productions, too. It also discusses two possible definitions of the relation of the direct derivation step used in the literature.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
