enow.com Web Search

Search results

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

    en.wikipedia.org/wiki/Cardinality

    The equivalence class of a set A under this relation, then, consists of all those sets which have the same cardinality as A. There are two ways to define the "cardinality of a set": The cardinality of a set A is defined as its equivalence class under equinumerosity. A representative set is designated for each equivalence class.

  3. Universal set - Wikipedia

    en.wikipedia.org/wiki/Universal_set

    In set theory, a universal set is a set which contains all objects, including itself. [1] ... always has strictly higher cardinality than the set itself.

  4. Cardinal number - Wikipedia

    en.wikipedia.org/wiki/Cardinal_number

    A bijective function, f: X → Y, from set X to set Y demonstrates that the sets have the same cardinality, in this case equal to the cardinal number 4. Aleph-null , the smallest infinite cardinal In mathematics , a cardinal number , or cardinal for short, is what is commonly called the number of elements of a set .

  5. Cantor's theorem - Wikipedia

    en.wikipedia.org/wiki/Cantor's_theorem

    Much more significant is Cantor's discovery of an argument that is applicable to any set, and shows that the theorem holds for infinite sets also. As a consequence, the cardinality of the real numbers, which is the same as that of the power set of the integers, is strictly larger than the cardinality of the integers; see Cardinality of the ...

  6. Glossary of set theory - Wikipedia

    en.wikipedia.org/wiki/Glossary_of_set_theory

    A variant of set theory that includes a universal set and possibly other non-standard axioms, focusing on what can be constructed or defined positively. Polish space A Polish space is a separable topological space homeomorphic to a complete metric space pow Abbreviation for "power (set)" power "Power" is an archaic term for cardinality power ...

  7. Power set - Wikipedia

    en.wikipedia.org/wiki/Power_set

    The power set of the set of natural numbers can be put in a one-to-one correspondence with the set of real numbers (see Cardinality of the continuum). The power set of a set S, together with the operations of union, intersection and complement, is a Σ-algebra over S and can be viewed as the prototypical example of a Boolean algebra.

  8. Element (mathematics) - Wikipedia

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

    The number of elements in a particular set is a property known as cardinality; informally, this is the size of a set. [5] In the above examples, the cardinality of the set A is 4, while the cardinality of set B and set C are both 3.

  9. Inclusion–exclusion principle - Wikipedia

    en.wikipedia.org/wiki/Inclusion–exclusion...

    The principle of inclusion–exclusion, combined with De Morgan's law, can be used to count the cardinality of the intersection of sets as well. Let ¯ represent the complement of A k with respect to some universal set A such that for each k. Then we have