比较多个上下文无关语言中的连续字母计数
Comparing consecutive letter counts in multiple context-free languages
摘要：
上下文无关文法不能对自然语言中的跨序列依赖进行建模。为了克服这个问题，Seki等人引入了一种称为$m$ -多上下文无关文法（$m$ -MCFG）的推广，它处理字符串的$m$ -元组。我们表明，$m$能够比较最多$2m$不同字母的连续出现次数。特别地，语言$\{a_1^{n_1} a_2^{n_2} \dots a_{k}^{n_{2m+1}} \mid n_1 \geq n_2 \geq \dots \geq n_{2m+1} \geq 0\}$是$(m+1)$ -多上下文无关，但不是$m$ -多上下文无关。
英文摘要：
Context-free grammars are not able to model cross-serial dependencies in 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 $\{a_1^{n_1} a_2^{n_2} \dots a_{k}^{n_{2m+1}} \mid n_1 \geq n_2 \geq \dots \geq n_{2m+1} \geq 0\}$ is $(m+1)$-multiple context-free, but not $m$-multiple context-free.
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。
