当前位置: X-MOL 学术Theor. Comput. Sci. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Comparing consecutive letter counts in multiple context-free languages
Theoretical Computer Science ( IF 0.9 ) Pub Date : 2021-03-26 , DOI: 10.1016/j.tcs.2021.03.034
Florian Lehner , Christian Lindorfer

Context-free grammars are not able to capture cross-serial dependencies occurring in some natural languages. To overcome this issue, Seki et al. introduced a generalization called m-multiple context-free grammars (m-MCFGs), which deal with m-tuples of strings. We show that m-MCFGs are capable of comparing the number of consecutive occurrences of at most 2m different letters. In particular, the language {a1n1a2n2a2m+1n2m+1|n1n2n2m+10} is (m+1)-multiple context-free, but not m-multiple context-free.



中文翻译:

比较多种上下文无关语言中的连续字母计数

上下文无关的语法无法捕获某些自然语言中出现的跨序列依赖项。为了克服这个问题,Seki等人。引入了一个称为m的多上下文无关文法(m -MCFGs)的概括,它处理字符串的m个元组。我们显示m -MCFGs能够比较最多2 m个不同字母的连续出现次数。特别是语言{一种1个ñ1个一种2个ñ2个一种2个+1个ñ2个+1个|ñ1个ñ2个ñ2个+1个0}+1个-多个上下文无关,但不是m-多个上下文无关。

更新日期:2021-04-21
down
wechat
bug