(definition)
Definition: A relation between exactly two items at a time, such as "greater than" (>), "not equal to" (≠), "proper subset of" (⊂), or "is connected to" (has an edge to) for vertices of a graph.
Generalization (I am a kind of ...)
relation.
Specialization (... is a kind of me.)
dictionary.
See also binary function, reflexive, symmetric, transitive, antisymmetric, irreflexive.
Note: One may think of a binary relation as a binary function whose range is {true, false}. For example since 3 > 2, GreaterThan(3, 2) = true.
Author: PEB
Vreda Pieterse's explanation of different representations of binary relations.
If you have suggestions, corrections, or comments, please get in touch with Paul Black.
Entry modified 4 September 2013.
HTML page formatted Mon Feb 2 13:10:39 2015.
Cite this as:
Paul E. Black, "binary relation", in
Dictionary of Algorithms and Data Structures [online], Vreda Pieterse and Paul E. Black, eds. 4 September 2013. (accessed TODAY)
Available from: http://www.nist.gov/dads/HTML/binaryRelation.html