A certain reducibility on admissible sets.
A few results on the complexity of classes of identifiable recursive function sets
A -set of natural numbers which is not enumerable by natural numbers.
About the admissible predicates on admissible sets.
Analytic determinacy and 0# A forcing-free proof of Harrington’s theorem
We prove the following theorem: Given a⊆ω and , if for some and all u ∈ WO of length η, a is , then a is . We use this result to give a new, forcing-free, proof of Leo Harrington’s theorem: -Turing-determinacy implies the existence of .
Arithmetische Prädikate über einem Bereich endlicher Automaten.