Classifying equivalence relations in the Ershov hierarchy© 2020, The Author(s). Computably enumerable equivalence relations (ceers) received
a lot
Jump inversions of algebraic structures and Σ-definability© 2019 WILEY-VCH Verlag GmbH & Co. KGa
A, Weinheim It is proved that for every countable structure
A survey of results on the d-c.e. and n-c.e. degrees© Springer International Publishing AG 2017.This paper is
a survey on the upper semilattices
Minimal generalized computable enumerations and high degrees enumerations of every infinite family computable with respect to
a high oracle is effectively infinite. We find