Year: 2023
Type: article
Abstract: We define upper Psi $\Psi $ Ψ -autoreducible sets given an autoreduction procedure upper Psi $\Psi $ Ψ . Then, we show that for any upper Psi $\Psi $ Ψ , a measurable class of upper Psi $\Psi $ Ψ -autoreducible sets has measure zero. Using this, we show that classes of cototal, uniformly introenumerable, introenumerable, and hyper-cototal enumeration degrees all have measure zero. By analyzing the arithmetical complexity of the classes of cototal sets and cototal enumeration degrees, we show that weakly 2-random sets cannot be cototal and weakly 3-random sets cannot be of cototal enumeration degree. Then, we see that this result is optimal by showing that there exists a 1-random cototal set and a 2-random set of cototal enumeration degree. For uniformly introenumerable degrees and introenumerable degrees, we utilize upper Psi $\Psi $ Ψ -autoreducibility again to show the optimal result that no weakly 3-random sets can have introenumerable enumeration degree. We also show that no 1-random set can be introenumerable.
Source: Journal of Symbolic Logic
DOI: 10.1017/jsl.2023.95
Author: ANG LI
Institution: University of Wisconsin–Madison
Language: English
Subfield: Computational Theory and Mathematics
Field: Computer Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,255
OpenAlex ID: W4389580840