Recursiveness of initial segments of Kleene's O
Reducing hyperarithmetic sequences
Rekursionszahlen und die Grzegorczyk-Hierarchie.
Relating automata-theoretic hierarchies to complexity-theoretic hierarchies
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 polynomial-time hierarchy. This extends a result of Burtschik and Vollmer on relationship between the Straubing and the polynomial hierarchies. In particular, this applies to the Boolean hierarchy and the plus-hierarchy.
Relating Automata-theoretic Hierarchies to Complexity-theoretic Hierarchies
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 polynomial-time hierarchy. This extends a result of Burtschik and Vollmer on relationship between the Straubing and the polynomial hierarchies. In particular, this applies to the Boolean hierarchy and the plus-hierarchy.