Cartesian product

mathematics (After Renee Descartes, French philosper and

mathematician) The Cartesian product of two sets A and B is

the set

A x B = (a, b) | a in A, b in B.

I.e. the product set contains all possible combinations of one

element from each set. The idea can be extended to products

of any number of sets.

If we consider the elements in sets A and B as points along

perpendicular axes in a two-dimensional space then the

elements of the product are the "Cartesian coordinates" of

points in that space.

See also tuple.

(1995-03-01)