Type theory

Mathematical theory of data types

In mathematical logic, and theoretical computer science, type theory is the study of formal systems that classify expressions or mathematical objects by their types. Roughly speaking, a type plays a similar role to that played by a data type in programming: it specifies what kind of thing an expression is and how it may be used. Type theories are used in the study of programming languages (type systems), formal logic, and the formalization of mathematics.

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