Elementary theory

In mathematical logic, an elementary theory is one that involves axioms using only finitary first-order logic, without reference to set theory or using any axioms which have consistency strength equal to set theory.

Saying that a theory is elementary is a weaker condition than saying it is algebraic.

gollark: Also. This is heresy, color is the right one and colour is the EVIL spelling.
gollark: I think... French does, though?
gollark: English definitely doesn't.
gollark: "Official language"? Most languages don't have official authorities.
gollark: Well, the standard English one.

References
  • Mac Lane and Moerdijk, Sheaves in Geometry and Logic: A First Introduction to Topos Theory, page 4.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.