👉 In mathematics, metatheory refers to a branch of mathematics that deals with abstract structures and their relationships. It is concerned with the study of mathematical concepts beyond the realm of concrete objects or specific instances, such as relations, functions, sets, and other abstract entities. Metatheory includes topics such as set theory, logic, category theory, and higher-order algebra. Metatheory can be divided into two main branches: the classical branch, which focuses on axiomatic systems and their properties,
