cofinite set
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Cofinite — In mathematics, a cofinite subset of a set X is a subset Y whose complement in X is a finite set. In other words, Y contains all but finitely many elements of X . If the complement is not finite, but it is countable, then one says the set is… … Wikipedia
Thick set — In mathematics, a thick set is a set of integers that contains arbitrarily long intervals. That is, given a thick set T, for every p in mathbb{N}, there is some n in mathbb{N} such that {n, n+1, n+2, ... , n+p } subset T.ee also*Syndetic set… … Wikipedia
Recursive set — In computability theory, a set of natural numbers is called recursive, computable or decidable if there is an algorithm which terminates after a finite amount of time and correctly decides whether or not a given number belongs to the set. A more… … Wikipedia
List of exceptional set concepts — This is a list of exceptional set concepts. In mathematics, and in particular in mathematical analysis, it is very useful to be able to characterise subsets of a given set X as small , in some definite sense, or large if their complement in X is… … Wikipedia
Simple set — In recursion theory a simple set is an example of a set which is recursively enumerable but not recursive. Definition A subset S of the natural numbers N is called simple if it satisfies the following properties # N S is infinite and contains no… … Wikipedia
Piecewise syndetic set — In mathematics, piecewise syndeticity is a notion of largeness of subsets of the natural numbers. Let mathcal{P} f(mathbb{N}) denote the set of finite subsets of mathbb{N}. Then a set S sub mathbb{N} is called piecewise syndetic if there exists G … Wikipedia
Maximal set — In recursion theory, the mathematical theory of computability, a maximal set is a coinfinite recursively enumerable subset A of the natural numbers such that for every further recursively enumerable subset B of the natural numbers, either B is… … Wikipedia
Boolean algebra — This article discusses the subject referred to as Boolean algebra. For the mathematical objects, see Boolean algebra (structure). Boolean algebra, as developed in 1854 by George Boole in his book An Investigation of the Laws of Thought,[1] is a… … Wikipedia
Boolean algebra (introduction) — Boolean algebra, developed in 1854 by George Boole in his book An Investigation of the Laws of Thought , is a variant of ordinary algebra as taught in high school. Boolean algebra differs from ordinary algebra in three ways: in the values that… … Wikipedia
T1 space — In topology and related branches of mathematics, T1 spaces and R0 spaces are particular kinds of topological spaces.The T1 and R0 properties are examples of separation axioms. Definitions Let X be a topological space and let x and y be points in… … Wikipedia
filter — 1. noun /ˈfɪltə,ˈfɪltɚ/ a) A device which separates a suspended, dissolved, or particulate matter from a fluid, solution, or other substance; any device that separates one substance from another. The collection of cofinite subsets of ℝ<!should … Wiktionary
