“…(1) If (-1) k f (k) (x) ≥ 0 for all k ≥ 0 and x ∈ (0, ∞), then we call f (x) a completely monotonic function on (0, ∞). See the review papers [22,31,36] and [35, Chapter IV]. f (x) is a completely monotonic function on (0, ∞), then we call f (x) a logarithmically completely monotonic function on (0, ∞).…”