Function spaces:The set of all functions from a domain A to a range B can be notated in several different ways: (a) A ??? B (b) BA The Cartesian product of two sets A and B: A X B this is the set of all ordered pairs (a, b) such that a is a member of A and b is a member of B: { (a,b) | a ??? A ??? b ??? B } currying Given a binary function f in (A X B) ??? C there is always a unary function g in B