嵌套词转导的流式性
Streamability of nested word transductions
AI总结：
本文研究嵌套词转导的流式评估问题，证明可见下推转换器的高度有界内存可判定性，并提出一个充分条件，使内存需求随词高二次增长，涵盖所有可确定化 VPT。
摘要：
我们考虑在流式（即单次从左到右遍历）环境下，使用有限内存评估嵌套词转导的问题。若一个转导 T 能够仅依赖于 T 的大小和输入词的高度进行评估，则称该转导为高度有界内存（HBM）。我们证明，对于由可见下推转换器（VPT）定义的嵌套词转导，判断其是否为 HBM 的问题在 coNPTime 时间内可判定。在这种情况下，所需内存量可能随词的高度呈指数增长。我们给出一个充分且可判定的条件，使得 VPT 能够以随词高度二次增长的内存进行评估。该条件定义了一类严格包含所有可确定化 VPT 的转导类。
英文摘要：
We consider the problem of evaluating in streaming (i.e., in a single left-to-right pass) a nested word transduction with a limited amount of memory. A transduction T is said to be height bounded memory (HBM) if it can be evaluated with a memory that depends only on the size of T and on the height of the input word. We show that it is decidable in coNPTime for a nested word transduction defined by a visibly pushdown transducer (VPT), if it is HBM. In this case, the required amount of memory may depend exponentially on the height of the word. We exhibit a sufficient, decidable condition for a VPT to be evaluated with a memory that depends quadratically on the height of the word. This condition defines a class of transductions that strictly contains all determinizable VPTs.
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。
