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arXiv · 2212.03786

Why the equivalence problem for unambiguous grammars has not been solved back in 1966?

Vladislav Makarov
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Abstract

In 1966, Semenov, by using a technique based on power series, suggested an algorithm that tells apart the languages described by an unambiguous grammar and a DFA. At the first glance, it may appear that the algorithm can be easily modified to yield a full solution of the equivalence problem for unambiguous grammars. This article shows why this hunch is, in fact, incorrect.

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Vladislav Makarov. 2022-12-07. Why the equivalence problem for unambiguous grammars has not been solved back in 1966?. https://arxiv.org/abs/2212.03786

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