cardinality

noun — 4 senses

cardinality

noun

UK /kɑːdɪˈnælɪti/ · US /kɑɹdɪˈnælɪti/

Etymology From cardinal + -ity.

1

Mathematics, Sciences, Set theory Of a set The number of elements a given set contains.

  • The empty set has a cardinality of zero.
  • The cardinality of a set A is the least ordinal α such that there exists a bijection between A and α. We sometimes use the notation #92;alpha#61;#124;A#124; to indicate this.2005, Johan de Jong, “Set Theory”, in The Stacks Project, retrieved 26 Feb 2018:
2 more examples
  • For fuzzy sets, the concept of set size or cardinality is both richer and more problematic than it is for crisp sets. It is richer because, as we shall see, we may use more than one kind of cardinality.2006, Michael Smithson, Jay Verkuilen, Fuzzy Set Theory: Applications in the Social Sciences, SAGE Publications, page 37:
  • Clearly, in this example, the sensitivity to the cardinalities takes the weaker form F#91;M(A)#93;#61;#92;overset#123;#61;#125;#123;A#125; of a single-valued function from the measure to the cardinality rather than the stronger form M(A)#61;f(#92;overset#123;#61;#125;#123;A#125;) of a function from the cardinality to the measure.2012, Adolf Grünbaum, Robert S. Cohen, Marx W. Wartofsky, Philosophical Problems of Space and Time, 2nd edition, Springer, page 487:
2

The number of terms that can inhabit a type; the possible values of a type.

  • For many types, such as String, the set of possible values is unlimited. Such types have an infinite cardinality.2021, Martin Odersky et al., chapter 19, in Programming in Scala, 5th edition, Artima, →ISBN:
3

Computing, Databases, Engineering, Mathematics, Natural sciences, Physical sciences, Sciences The property of a relationship between a database table and another one, specifying whether it is one-to-one, one-to-many, many-to-one, or many-to-many.

4

Lifestyle, Religion The status of being cardinalitial

Related terms
cardinal, aleph, cardinal number, multiplicity

Entry derived from the Wiktionary, under licence CC BY-SA 4.0 — list of authors.