(mathematics) By means of, or in terms of, number theory.

Alternative spelling of set theoretically

(mathematics) In a manner which uses graph theory / (mathematics) In the sense of graph theory

(mathematics) In a manner which uses set theory / (mathematics) In the sense of set theory

(mathematics, number theory) The branch of number theory in which number-theoretic questions are expressed in terms of properties of algebraic number fields or related objects, and studied using techniques from algebra.

A political theory that holds that control of Eurasia and Africa (the World Island) is achieved via control of the countries bordering the Soviet Union

An interdisciplinary branch of engineering and mathematics, dealing with the control of the behavior of dynamical systems.

Alternative spelling of physicotheology

(mathematics) A branch of applied mathematics and engineering involving the quantification of information sent over a communication channel, disregarding the meaning of the sent messages, exemplified by the noisy-channel coding theorem.

(statistics and mathematics, singular only) The theorem that states that if the sum of independent identically distributed random variables has a finite variance, then it will be approximately normally distributed.