Jump to content

Non-standard model

From Wikipedia, the free encyclopedia
This is an old revision of this page, as edited by Hyacinth (talk | contribs) at 23:41, 18 October 2014 (References: {{Mathematical logic}}). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
See also Interpretation (logic)

In model theory, a discipline within mathematical logic, a non-standard model is a model of a theory that is not isomorphic to the intended model (or standard model). If the intended model is infinite and the language is first-order, then the Löwenheim–Skolem theorems guarantee the existence of non-standard models. The non-standard models can be chosen as elementary extensions or elementary substructures of the intended model.

Non-standard models are studied in set theory, non-standard analysis and non-standard models of arithmetic.

References