 Categorical theory

A theory is $\kappa$-categorical when all of its models of cardinality $\kappa$ are isomorphic.

Categorical theory, or category theory, is a branch of mathematics that deals with abstract structures and relations between them. It was developed in the mid-20th century, primarily by mathematicians Samuel Eilenberg and Saunders Mac Lane. The core idea of category theory is to provide a unifying framework for understanding and analyzing mathematical concepts and structures across different fields.