English

Pseudo-jump inversion and SJT-hard sets

Logic 2011-10-03 v1

Abstract

There are noncomputable c.e.\ sets, computable from every SJT-hard c.e.\ set. This yields a natural pseudo-jump operator, increasing on all sets, which cannot be inverted back to a minimal pair or even avoiding an upper cone.

Cite

@article{arxiv.1109.6752,
  title  = {Pseudo-jump inversion and SJT-hard sets},
  author = {Rodney G. Downey and Noam Greenberg},
  journal= {arXiv preprint arXiv:1109.6752},
  year   = {2011}
}

Comments

34 pages

R2 v1 2026-06-21T19:13:03.618Z