English

A Note on Extensions of Infinitary Logic

Logic 2007-05-23 v1

Abstract

We show that a strong form of the so called Lindstrom's Theorem fails to generalize to extensions of L_{kappa,omega} and L_{kappa,kappa}: For weakly compact kappa there is no strongest extension of L_{kappa,omega} with the (kappa,kappa)-compactness property and the Lowenheim-Skolem theorem down to kappa. With an additional set-theoretic assumption, there is no strongest extension of L_{kappa,kappa} with the (kappa,kappa)-compactness property and the Lowenheim-Skolem theorem down to <kappa.

Cite

@article{arxiv.math/0009080,
  title  = {A Note on Extensions of Infinitary Logic},
  author = {Saharon Shelah and Jouko Väänänen},
  journal= {arXiv preprint arXiv:math/0009080},
  year   = {2007}
}
R2 v1 2026-07-22T16:34:38.135Z