Аннотация:
We define and study an effective version of the Wadge hierarchy in computable quasi-Polish spaces which include most spaces of interest for computable analysis. Along with hierarchies of sets we study hierarchies of $k$-partitions which are interesting on their own. We show that levels of such hierarchies are preserved by the computable effectively open surjections, that if the effective Hausdorff-Kuratowski theorem holds in the Baire space then it holds in every computable quasi-Polish space, and we extend the effective Hausdorff theorem to $k$-partitions.
Victor Selivanov, Vasco Brattka, Noam Greenberg, Iskander Kalimullin, Mariya Soskova, “Non-collapse of the effective Wadge hierarchy”, COM, 11:3-4 (2022), 335
Victor Selivanov, Lecture Notes in Computer Science, 13359, Revolutions and Revelations in Computability, 2022, 287
Victor Selivanov, Lecture Notes in Computer Science, 12813, Connecting with Computability, 2021, 407