
infimum
or greatest lower bound (abbrev. inf, glb), n. the unique largest member of the set of lower bounds for some given set, equal to its minimum if the given set has a least member. The infimum θ of a set T may be defined as satisfying the two conditions, that θ ≤ t for all t in T, and that for all t > θ there is a t' < t in T. For example, the geometric sequence 1/2, 1/4, 1/8,... has as a lower bound every real number less than or equal to zero; it has no least member, and so no minimum but its infimum is 0. Compare supremum.