lowest upper bound (original) (raw)

A lowest upper bound of T, when it exists, is unique.

Greatest lower bound is defined similarly: a greatest lower bound, or infimum, of T is a lower bound x of T with the property that x≥y for every lower bound y of T. The greatest lower bound of T, when it exists, is denoted inf⁡(T).

If A={a1,a2,…,an} is a finite set, then the supremum of A is simply max⁡(A), and the infimum of A is equal to min⁡(A).