New perspectives in algebraic logic, from neat embeddings to Erdos graphs

Abstract

The notion of neat reducts is an old venerable notion in cylindric algebra theory invented by Henkin. This notion is regaining momentum. In this paper we explain why. This notion is discussed in connection to the algebraic notions of representability and complete representability, and the corresponding metalogical ones of completeness and omitting types, particularly for finite variable fragments. Also it is shown how such a notion has found intersection with non-trivial topics in model theory (like finite forcing) and set theory (forcing).