On the complexity of the universality and inclusion problems for unambiguous context-free grammars (technical report)
On the complexity of the universality and inclusion problems for unambiguous context-free grammars (technical report)
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关于明确上下文无关语法的普遍性和包含问题的复杂性(技术报告)
DOI:
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发表时间:
2020
期刊:
影响因子:
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通讯作者:
Lorenzo Clemente
中科院分区:
文献类型:
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作者:
Lorenzo Clemente
We study the computational complexity of universality and inclusion problems for unambiguous finite automata and context-free grammars. We observe that several such problems can be reduced to the universality problem for unambiguous context-free grammars. The latter problem has long been known to be decidable and we propose a PSPACE algorithm that works by reduction to the zeroness problem of recurrence equations with convolution. We are not aware of any non-trivial complexity lower bounds. However, we show that computing the coin-flip measure of an unambiguous context-free language, a quantitative generalisation of universality, is hard for the long-standing open problem SQRTSUM.
DOI:
10.4230/lipics.stacs.2010.2468
发表时间:
2010
期刊:
ArXiv
影响因子:
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作者:
Javier Esparza;Andreas Gaiser;Stefan Kiefer
通讯作者:
Stefan Kiefer