cardinality (plural cardinalities)
- (set theory) Of a set, the number of elements it contains.
- The empty set has a cardinality of zero.
2005 March 22, Johan de Jong, “Set Theory”, in The Stacks Project, retrieved 2018-2-26:
- 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 to indicate this.
- (data modeling, databases) 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.
- (religion) The status of a cardinal
- (in set theory): power
in set theory