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arXiv 2103.05485cs.FL
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将不确定双向自动机转化为确定线性时间小型机

Converting Nondeterministic Two-Way Automata into Small Deterministic Linear-Time Machines

Bruno Guillon, Giovanni Pighizzini, Luca Prigioniero, Daniel Průša

摘要:

1978年,Sakoda和Sipser提出了一个问题,即把双向和单向的非确定自动机转换成等价的双向确定自动机的代价,即表示的大小。尽管做了所有的尝试,这个问题只在特定的情况下得到了回答(例如,模拟自动机类或模拟自动机类的限制)。然而,这个问题在一般情况下仍然是开放的,最著名的上限是指数。我们提出了一种新的方法,其中不受限制的非确定性有限自动机的模拟确定性模型扩展双向确定性有限自动机,支付多项式的大小增加。事实上,我们研究的成本转换的非确定性有限自动机到一些变种的单磁带确定性图灵机工作在线性时间,即亨尼机,减重图灵机,减重亨尼机。所有这些变体都具有相同的计算能力:它们是正则语言类的特征。

英文摘要:

In 1978 Sakoda and Sipser raised the question of the cost, in terms of size of representations, of the transformation of two-way and one-way nondeterministic automata into equivalent two-way deterministic automata. Despite all the attempts, the question has been answered only for particular cases (e.g., restrictions of the class of simulated automata or of the class of simulating automata). However the problem remains open in the general case, the best-known upper bound being exponential. We present a new approach in which unrestricted nondeterministic finite automata are simulated by deterministic models extending two-way deterministic finite automata, paying a polynomial increase of size only. Indeed, we study the costs of the conversions of nondeterministic finite automata into some variants of one-tape deterministic Turing machines working in linear time, namely Hennie machines, weight-reducing Turing machines, and weight-reducing Hennie machines. All these variants are known to share the same computational power: they characterize the class of regular languages.

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。

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