• Media type: E-Article
  • Title: Hanf number of omitting type for simple first-order theories
  • Contributor: Shelah, Saharon
  • imprint: Cambridge University Press (CUP), 1979
  • Published in: Journal of Symbolic Logic
  • Language: English
  • DOI: 10.2307/2273125
  • ISSN: 1943-5886; 0022-4812
  • Keywords: Logic ; Philosophy
  • Origination:
  • Footnote:
  • Description: <jats:title>Abstract</jats:title><jats:p>Let <jats:italic>T</jats:italic> be a complete countable first-order theory such that every ultrapower of a model of <jats:italic>T</jats:italic> is saturated. If <jats:italic>T</jats:italic> has a model omitting a type <jats:italic>p</jats:italic> in every cardinality &lt; ℶ<jats:sub>′</jats:sub>, then <jats:italic>T</jats:italic> has a model omitting <jats:italic>p</jats:italic> in every cardinality. There is also a related theorem, and an example showing the ℶ<jats:sub>′</jats:sub> cannot be improved.</jats:p>