We show that some natural refinements of the Straubing and Brzozowski hierarchies correspond (via the so called leaf-languages) step by step to similar refinements of the polynom...
Abstract. The maximum intersection problem for a matroid and a greedoid, given by polynomial-time oracles, is shown NP-hard by expressing the satisfiability of boolean formulas in...
Abstract. Generalising modules over associative rings, the notion of modules for an endofunctor of any category is well established and useful in large parts of mathematics includi...
This paper presents the prediction-preserving reducibility with membership queries (pwm-reducibility) on formal languages, in particular, simple CFGs and finite unions of regular ...