﻿

# sum set, axiom of

The axiom of Zermelo–Fraenkel set theory providing that for each set S the collection x :(∃y )(y ∈ S & xy ), the union of S, is a set.

Philosophy dictionary. . 2011.

### Look at other dictionaries:

• Axiom of choice — This article is about the mathematical concept. For the band named after it, see Axiom of Choice (band). In mathematics, the axiom of choice, or AC, is an axiom of set theory stating that for every family of nonempty sets there exists a family of …   Wikipedia

• set theory — the branch of mathematics that deals with relations between sets. [1940 45] * * * Branch of mathematics that deals with the properties of sets. It is most valuable as applied to other areas of mathematics, which borrow from and adapt its… …   Universalium

• Zermelo–Fraenkel set theory — The first rigorous axiomatization of set theory was presented by Ernst Zermelo (1871–1953) in 1908, and its development by A. A. Fraenkel (1891–1965), adding the axiom of replacement, is known as ZF. If the axiom of choice is added it is known as …   Philosophy dictionary

• König's theorem (set theory) — For other uses, see König s theorem. In set theory, König s theorem (named after the Hungarian mathematician Gyula König) colloquially states that if the axiom of choice holds, I is a set, mi and ni are cardinal numbers for every i in I , and m i …   Wikipedia

• Non-measurable set — This page gives a general overview of the concept of non measurable sets. For a precise definition of measure, see Measure (mathematics). For various constructions of non measurable sets, see Vitali set, Hausdorff paradox, and Banach–Tarski… …   Wikipedia

• Vitali set — In mathematics, a Vitali set is an elementary example of a set of real numbers that is not Lebesgue measurable. The Vitali theorem is the existence theorem that there are such sets. It is a non constructive result. The naming is for Giuseppe… …   Wikipedia

• Morse–Kelley set theory — In the foundation of mathematics, Morse–Kelley set theory (MK) or Kelley–Morse set theory (KM) is a first order axiomatic set theory that is closely related to von Neumann–Bernays–Gödel set theory (NBG). While von Neumann–Bernays–Gödel set theory …   Wikipedia

• Empty set — ∅ redirects here. For similar looking symbols, see Ø (disambiguation). The empty set is the set containing no elements. In mathematics, and more specifically set theory, the empty set is the unique set having no elements; its size or cardinality… …   Wikipedia

• Internal Set Theory — Die Internal Set Theory (keine übliche deutsche Übersetzung bekannt) ist eine rein syntaktische Version der Nichtstandard Analysis, die 1977 von Edward Nelson eingeführt wurde. Anders als im modelltheoretischen Ansatz werden Infinitesimale nicht… …   Deutsch Wikipedia

• Universally measurable set — In mathematics, a subset A of a Polish space X is universally measurable if it is measurable with respect to every complete probability measure on X that measures all Borel subsets of X. In particular, a universally measurable set of reals is… …   Wikipedia