In a 1975 paper [8], Heinig established the following three inequalities:

where A = p/(p + s − λ) with p, s, λ real numbers satisfying p + s > λ,p > 0;

where B = p/(2p + sp − λ −1) with p, s, λ real numbers satisfying 2p +sp > λ, + 1, p > 0;

where
is a sequence of nonnegative real numbers,

and C = p[l + l/(p + s−λ)] with p, s, λ real numbers satisfying s > 0, p ≥ 1, and p +s > λ 0.