ON TREES WITHOUT HYPERIMMUNE BRANCHES
Keng Meng Ng, Frank Stephan, Yue Yang, Liang Yu · Lecture notes in computer science · 2022
Abstract The current work includes a result announced in the year 2012 which was unproven for 10 years. The result shows that there is a co-r.e. tree with uncountably many infinite branches such that the nonisolated infinite branches of the constructed tree are all nonrecursive, generalised low, and hyperimmune-free and form a perfect tree. This article is the journal version of two conference articles from 2012 and 2022; the article contains the main result proved in 2022 and also the other major results from 2012.