(geometry) a theorem stating that if a set of points P_i lying on a line is isometrically mapped to points P_i' on a different line, then the midpoints of the segments P_iP_i' also lie on a line.

(mathematics) A result about the decomposability of measure spaces, playing an important role in the theory of Banach spaces. In brief, it states that every complete measure space is decomposable into "non-atomic parts" (copies of products of the unit interval [0,1] on the reals), and "purely atomic parts", using the counting measure on some discrete space.

(game theory) A theorem about finite two-person games of perfect information in which the players move alternately and chance does not affect the decision-making process. It states that if the game cannot end in a draw, then one of the two players must have a winning strategy, i.e. force a win.

Abbreviation of Kochen-Specker theorem.

A theorem stating that, if we have free will in the sense that our choices are not a function of the past, then, subject to certain assumptions, so must some elementary particles.

(mathematics) A formula for the exponent of the highest power of a prime number that divides a given binomial coefficient.

(economics) The idea that capital accumulation is equal to production minus consumption.

(mathematics) A certain approximation theorem in complex analysis.

(geometry) A theorem stating that if A, B, and C are distinct points on a circle where the line AC is a diameter, the angle ABC is a right angle.

(mathematics) A result in combinatorics, stating that every set of integers with positive natural density contains a k-term arithmetic progression for every k.