论文标题
为什么在1966年没有解决明确语法的等效问题？
Why the equivalence problem for unambiguous grammars has not been solved back in 1966?
论文作者
论文摘要
1966年，Semenov通过使用基于功率系列的技术，提出了一种算法，该算法讲述了由明确的语法和DFA所描述的语言。乍一看，似乎可以轻松地修改算法，从而产生明确的语法等效问题的完整解决方案。本文显示了为什么这种直觉实际上是不正确的。
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.
