English

Constructing Ultrapowers from Elementary Extensions of Full Clones

Logic 2012-07-03 v1

Abstract

Let AA be an infinite set. Let Ω(A)\Omega(A) be the algebra over AA where every constant is a fundamental constant and every finitary function is a fundamental operation. We shall give a method of representing any algebra L\mathcal{L} in the variety generated by Ω(A)\Omega(A) as limit reduced powers and even direct limits of limit reduced powers of L\mathcal{L}. If the algebra L\mathcal{L} is elementarily equivalent to Ω(A)\Omega(A), then this construction represents Ω(A)\Omega(A) as a limit ultrapower and also as direct limits of limit ultrapowers of Ω(A)\Omega(A). This method therefore gives a method of representing Boolean ultrapowers and other generalizations of the ultrapower construction as limit ultrapowers and direct limits of limit ultrapowers.

Keywords

Cite

@article{arxiv.1207.0118,
  title  = {Constructing Ultrapowers from Elementary Extensions of Full Clones},
  author = {Joseph Van Name},
  journal= {arXiv preprint arXiv:1207.0118},
  year   = {2012}
}
R2 v1 2026-06-21T21:28:34.155Z