meager subset

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• Luzin set — In real analysis and descriptive set theory, a Luzin set (or Lusin set), named for N. N. Luzin, is an uncountable subset A of the reals such that every uncountable subset of A is nonmeager; that is, of second Baire category. Equivalently, A is an …   Wikipedia

• Ideal (set theory) — In the mathematical field of set theory, an ideal is a collection of sets that are considered to be small or negligible . Every subset of an element of the ideal must also be in the ideal (this codifies the idea that an ideal is a notion of… …   Wikipedia

• Meagre set — In the mathematical fields of general topology and descriptive set theory, a meagre set (also called a meager set or a set of first category) is a set that, considered as a subset of a (usually larger) topological space, is in a precise sense… …   Wikipedia

• Complete Boolean algebra — This article is about a type of mathematical structure. For complete sets of Boolean operators, see Functional completeness. In mathematics, a complete Boolean algebra is a Boolean algebra in which every subset has a supremum (least upper bound) …   Wikipedia

• Property of Baire — A subset A of a topological space X has the property of Baire (Baire property) if it differs from an open set by a meager set; that is, if there is an open: Usubseteq Xsuch that: ADelta Uis meager (here, Delta; denotes the symmetric… …   Wikipedia

• climate — /kluy mit/, n. 1. the composite or generally prevailing weather conditions of a region, as temperature, air pressure, humidity, precipitation, sunshine, cloudiness, and winds, throughout the year, averaged over a series of years. 2. a region or… …   Universalium

• Grothendieck topology — In category theory, a branch of mathematics, a Grothendieck topology is a structure on a category C which makes the objects of C act like the open sets of a topological space. A category together with a choice of Grothendieck topology is called a …   Wikipedia

• Thomae's function — If you are having difficulty understanding this article, you might wish to learn more about algebra, functions, and mathematical limits. Thomae s function, also known as the popcorn function, the raindrop function, the ruler function or the… …   Wikipedia

• Determinacy — Determined redirects here. For the 2005 heavy metal song, see Determined (song). For other uses, see Indeterminacy (disambiguation). In set theory, a branch of mathematics, determinacy is the study of under what circumstances one or the other… …   Wikipedia

• Derivative — This article is an overview of the term as used in calculus. For a less technical overview of the subject, see Differential calculus. For other uses, see Derivative (disambiguation) …   Wikipedia

• Woodin cardinal — In set theory, a Woodin cardinal (named for W. Hugh Woodin) is a cardinal number λ such that for all : f : λ rarr; λthere exists:κ < λ with { f (β)|β …   Wikipedia