Search results
Results From The WOW.Com Content Network
To investigate the left distributivity of set subtraction over unions or intersections, consider how the sets involved in (both of) De Morgan's laws are all related: () = = () always holds (the equalities on the left and right are De Morgan's laws) but equality is not guaranteed in general (that is, the containment might be strict).
Given sets X and Y, a heterogeneous relation R over X and Y is a subset of { (x,y) | x∈X, y∈Y}. [ 2 ] [ 22 ] When X = Y , the relation concept described above is obtained; it is often called homogeneous relation (or endorelation ) [ 23 ] [ 24 ] to distinguish it from its generalization.
The most general notion is the union of an arbitrary collection of sets, sometimes called an infinitary union. If M is a set or class whose elements are sets, then x is an element of the union of M if and only if there is at least one element A of M such that x is an element of A. [11] In symbols:
A set is described by listing elements separated by commas, or by a characterizing property of its elements, within braces { }. [8] Since sets are objects, the membership relation can relate sets as well, i.e., sets themselves can be members of other sets. A derived binary relation between two sets is the subset relation, also called set inclusion.
In particular, totally ordered sets can also be referred to as "ordered sets", especially in areas where these structures are more common than posets. Some authors use different symbols than ≤ {\displaystyle \leq } such as ⊑ {\displaystyle \sqsubseteq } [ 6 ] or ⪯ {\displaystyle \preceq } [ 7 ] to distinguish partial orders from total orders.
The intersection of all the convex sets that contain a given subset A of Euclidean space is called the convex hull of A. It is the smallest convex set containing A . A convex function is a real-valued function defined on an interval with the property that its epigraph (the set of points on or above the graph of the function) is a convex set.
Set-builder notation can be used to describe a set that is defined by a predicate, that is, a logical formula that evaluates to true for an element of the set, and false otherwise. [2]
In mathematics, the limit of a sequence of sets,, … (subsets of a common set ) is a set whose elements are determined by the sequence in either of two equivalent ways: (1) by upper and lower bounds on the sequence that converge monotonically to the same set (analogous to convergence of real-valued sequences) and (2) by convergence of a sequence of indicator functions which are themselves ...