enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Subset - Wikipedia

    en.wikipedia.org/wiki/Subset

    In mathematics, a set A is a subset of a set B if all elements of A are also elements of B; ... For example, for these authors, it is true of every set A that ...

  3. Set (mathematics) - Wikipedia

    en.wikipedia.org/wiki/Set_(mathematics)

    A third pair of operators ⊂ and ⊃ are used differently by different authors: some authors use A ⊂ B and B ⊃ A to mean A is any subset of B (and not necessarily a proper subset), [33] [24] while others reserve A ⊂ B and B ⊃ A for cases where A is a proper subset of B. [31] Examples: The set of all humans is a proper subset of the set ...

  4. Dense set - Wikipedia

    en.wikipedia.org/wiki/Dense_set

    In topology and related areas of mathematics, a subset A of a topological space X is said to be dense in X if every point of X either belongs to A or else is arbitrarily "close" to a member of A — for instance, the rational numbers are a dense subset of the real numbers because every real number either is a rational number or has a rational number arbitrarily close to it (see Diophantine ...

  5. Empty set - Wikipedia

    en.wikipedia.org/wiki/Empty_set

    The only subset of the empty set is the empty set itself; equivalently, the power set of the empty set is the set containing only the empty set. The number of elements of the empty set (i.e., its cardinality) is zero. The empty set is the only set with either of these properties. For any set A: The empty set is a subset of A

  6. Partition of a set - Wikipedia

    en.wikipedia.org/wiki/Partition_of_a_set

    In mathematics, a partition of a set is a grouping of its elements into non-empty subsets, in such a way that every element is included in exactly one subset. Every equivalence relation on a set defines a partition of this set, and every partition defines an equivalence relation.

  7. Infimum and supremum - Wikipedia

    en.wikipedia.org/wiki/Infimum_and_supremum

    As an example, let be the set of all finite subsets of natural numbers and consider the partially ordered set obtained by taking all sets from together with the set of integers and the set of positive real numbers +, ordered by subset inclusion as above.

  8. Element (mathematics) - Wikipedia

    en.wikipedia.org/wiki/Element_(mathematics)

    In the above examples, the cardinality of the set A is 4, while the cardinality of set B and set C are both 3. An infinite set is a set with an infinite number of elements, while a finite set is a set with a finite number of elements. The above examples are examples of finite sets.

  9. Family of sets - Wikipedia

    en.wikipedia.org/wiki/Family_of_sets

    In set theory and related branches of mathematics, a family (or collection) can mean, depending upon the context, any of the following: set, indexed set, multiset, or class. A collection of subsets of a given set is called a family of subsets of , or a family of sets over .