“…Here J stands for jumps, since the considered functions may jump at some points of K. If the fractal set K is totally disconnected, then these spaces coincide with the Lipschitz spaces Lip(α, p, q; m; K) also introduced in [10]. The latter are a generalization of the more classical spaces Lip(α, p, q; K) introduced in [11] since Lip(α, p, q; [12]. Since this is sufficient for what follows, we will focus on the case when K = Γ ∞ and p = q.…”