**Mathematical logic** (also known as **symbolic logic**) is a subfield of mathematics with close connections to the foundations of mathematics, theoretical computer science and philosophical logic. The field includes both the mathematical study of logic and the applications of formal logic to other areas of mathematics. The unifying themes in mathematical logic include the study of the expressive power of formal systems and the deductive power of formal proof systems.

Mathematical logic is often divided into the fields of set theory, model theory, recursion theory, and proof theory. These areas share basic results on logic, particularly first-order logic, and definability. In computer science (particularly in the ACM Classification) mathematical logic encompasses additional topics not detailed in this article; see logic in computer science for those.

Since its inception, mathematical logic has both contributed to, and has been motivated by, the study of foundations of mathematics. This study began in the late 19th century with the development of axiomatic frameworks for geometry, arithmetic, and analysis. In the early 20th century it was shaped by David Hilbert's program to prove the consistency of foundational theories. Results of Kurt GĂ¶del, Gerhard Gentzen, and others provided partial resolution to the program, and clarified the issues involved in proving consistency. Work in set theory showed that almost all ordinary mathematics can be formalized in terms of sets, although there are some theorems that cannot be proven in common axiom systems for set theory. Contemporary work in the foundations of mathematics often focuses on establishing which parts of mathematics can be formalized in particular formal systems (as in reverse mathematics) rather than trying to find theories in which all of mathematics can be developed.

Read more about Mathematical Logic: Subfields and Scope, History, Formal Logical Systems, Set Theory, Model Theory, Recursion Theory, Proof Theory and Constructive Mathematics, Connections With Computer Science, Foundations of Mathematics

### Famous quotes containing the words mathematical and/or logic:

“The circumstances of human society are too complicated to be submitted to the rigour of *mathematical* calculation.”

—Marquis De Custine (1790–1857)

“The American Constitution, one of the few modern political documents drawn up by men who were forced by the sternest circumstances to think out what they really had to face instead of chopping *logic* in a university classroom.”

—George Bernard Shaw (1856–1950)