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The pattern of consistency strength for membership in a computably enumerable set
Abstract
Every computable preorder relation on the natural numbers is the order of consistency strength for the membership assertions "n∈ A" in some computably enumerable set A. Moreover, for every computably enumerable list of theories T0,T1,T2,…, each extending PA, there is a computably enumerable set A such that each Tn is equiconsistent over PA with the membership assertion n∈ A. And similarly for both results when using instead the nonmembership assertions n∉ A.
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BibTeX
@misc{hamkins2026pattern,
title = {{The pattern of consistency strength for membership in a computably enumerable set}},
author = {Joel David Hamkins and Atticus Stonestrom},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.24919},
eprint = {2610.24919},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.24919},
}
RIS
TY - UNPB
TI - The pattern of consistency strength for membership in a computably enumerable set
AU - Joel David Hamkins
AU - Atticus Stonestrom
PY - 2026
DA - 2026/10/17
PB - arXiv
DO - 10.48550/arxiv.2610.24919
UR - https://arxiv.org/abs/2610.24919
AB - Every computable preorder relation on the natural numbers is the order of consistency strength for the membership assertions "n∈ A" in some computably enumerable set A. Moreover, for every computably enumerable list of theories T_0,T_1,T_2,…, each extending PA, there is a computably enumerable set A such that each T_n is equiconsistent over PA with the membership assertion n∈ A. And similarly for both results when using instead the nonmembership assertions n∉ A.
ER -