Counting problems for Parikh images

Given finite-state automata (or context-free grammars) A, B over the same alphabet and a Parikh vector ~p, we study the complexity of deciding whether the number of words in the language of A with Parikh image ~p is greater than the number of such words in the language of B. Recently, this problem t...

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Bibliographic Details
Main Authors: Haase, CJ, Kiefer, S, Lohrey, M
Format: Conference item
Published: Schloss Dagstuhl 2017
Description
Summary:Given finite-state automata (or context-free grammars) A, B over the same alphabet and a Parikh vector ~p, we study the complexity of deciding whether the number of words in the language of A with Parikh image ~p is greater than the number of such words in the language of B. Recently, this problem turned out to be tightly related to the cost problem for weighted Markov chains. We classify the complexity according to whether A and B are deterministic, the size of the alphabet, and the encoding of ~p (binary or unary).