2026/02/20 by Krasimir Yordzhev · 1 voice
Computer Science · Mathematics · #cs.FL #math.CO
paper · pdf · doi:10.2298/fil2412157y
The work investigates the problem of whether a context-free language is a subset of a group language. A.~V. Anisimov has shown that the problem of determining the unambiguity of finite automata is a special case of this problem. Then the question of finding polynomial algorithm verifying the inclusion of context-free languages in group languages naturally arises. The article focuses on this open problem. For the purpose, the paper describes an unconventional method of description of context-free languages, namely a representation with the help of a finite digraph whose arcs are labelled with a specially defined monoid U. Also, we define a semiring SU whose elements are the set 2U of all subsets of U and with operations - product and union of the elements of 2U. The described algorithm executes no more than O(n3) operations in SU.