ABSTRACT
ℕ0 and ℕ denote the sets of the non-negative resp. positive integers; https://www.w3.org/1998/Math/MathML"> A , B … https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780138747022/abb99e87-ffb7-4196-a4c4-acb0033e3d6a/content/eq711.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> denote sets of positive integers, and their counting functions are denoted by A(x), B(x),…, so that, e.g., https://www.w3.org/1998/Math/MathML"> A ( x ) = | { a : a ≤ x , a ∈ A } | . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780138747022/abb99e87-ffb7-4196-a4c4-acb0033e3d6a/content/eq712.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>
