“…The function Φ and the (DC) doubling property. By defining (6.1) for Φ as in (7.1), for X = (x, z), X 0 = (x 0 , z 0 ) ∈ R n+1 , we have for every z, z , z ∈ R. Now, since µ ϕ ∈ (DC) ϕ and h s ∈ (DC) hs , from [11,Lemma 6] it follows that Φ, being the tensor sum of ϕ and h s , satisfies Φ ∈ (DC) Φ with constants depending only on the (DC) constants for µ ϕ , dimension n, and s. In addition, the condition µ Φ ∈ (DC) Φ is quantitatively equivalent to the existence of K ≥ 1 such that…”