Descriptive set theory — In mathematical logic, descriptive set theory is the study of certain classes of well behaved subsets of the real line and other Polish spaces. As well as being one of the primary areas of research in set theory, it has applications to other… … Wikipedia
Von Neumann–Bernays–Gödel set theory — In the foundations of mathematics, von Neumann–Bernays–Gödel set theory (NBG) is an axiomatic set theory that is a conservative extension of the canonical axiomatic set theory ZFC. A statement in the language of ZFC is provable in NBG if and only … Wikipedia
List of set theory topics — Logic portal Set theory portal … Wikipedia
Tree (descriptive set theory) — In descriptive set theory, a tree on a set X is a set of finite sequences of elements of X that is closed under subsequences. More formally, it is a subset T of X^{ … Wikipedia
Projection (relational algebra) — IntroductionIn relational algebra, a projection is a unary operation written as pi {a 1, ...,a n}( R ) where a 1,...,a n is a set of attribute names. The result of such projection is defined as the set obtained when the components of the tuple R… … Wikipedia
Projection — Contents 1 Chemistry 2 Mathematics 3 Other 4 See also … Wikipedia
Projection (mathematics) — Commutativity of this diagram is the universality of projection π, for any map f and set X. Generally speaking, in mathematics, a projection is a mapping of a set (or of a mathematical structure) which is idempotent, which means that a projection … Wikipedia
Projection-valued measure — In mathematics, particularly functional analysis a projection valued measure is a function defined on certain subsets of a fixed set and whose values are self adjoint projections on a Hilbert space. Projection valued measures are used to express… … Wikipedia
Analytic set — This article is about analytic sets as defined in descriptive set theory. There is another notion in the context of analytic varieties. In descriptive set theory, a subset of a Polish space X is an analytic set if it is a continuous image of a… … Wikipedia
Number theory — A Lehmer sieve an analog computer once used for finding primes and solving simple diophantine equations. Number theory is a branch of pure mathematics devoted primarily to the study of the integers. Number theorists study prime numbers (the… … Wikipedia
