English

A proof of completeness for continuous first-order logic

Logic 2014-02-10 v1

Abstract

The primary purpose of this article is to show that a certain natural set of axioms yields a completeness result for continuous first-order logic. In particular, we show that in continuous first-order logic a set of formulae is (completely) satisfiable if (and only if) it is consistent. From this result it follows that continuous first-order logic also satisfies an \emph{approximated} form of strong completeness, whereby Σφ\Sigma\vDash\varphi (if and) only if Σφ\dotminus2n\Sigma\vdash\varphi\dotminus 2^{-n} for all n<ωn<\omega. This approximated form of strong completeness asserts that if Σφ\Sigma\vDash\varphi, then proofs from Σ\Sigma, being finite, can provide arbitrary better approximations of the truth of φ\varphi.

Keywords

Cite

@article{arxiv.0903.4051,
  title  = {A proof of completeness for continuous first-order logic},
  author = {Itaï Ben Yaacov and Arthur Paul Pedersen},
  journal= {arXiv preprint arXiv:0903.4051},
  year   = {2014}
}
R2 v1 2026-06-21T12:43:44.515Z