Definition: A computation which takes some inputs and yields an output. Any particular input may yield different outputs at different times. Formally, a mapping from each element in the domain to one or more elements in the range.

Specialization (... is a kind of me.)
function, binary relation.

Note: Cosine is a function, since every angle has a specific cosine. Its inverse cos-1(x) is a relation, since a cosine value maps to many (for this relation, infinitely many) angles.

Author: PEB

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Entry modified 18 December 2003.
HTML page formatted Mon Feb 2 13:10:40 2015.

Cite this as:
Paul E. Black, "relation", in Dictionary of Algorithms and Data Structures [online], Vreda Pieterse and Paul E. Black, eds. 18 December 2003. (accessed TODAY) Available from: