“…The pioneers works on this theory, centered around the concept of ψ-hyperholomorphic functions defined on domains in R 3 (or R 4 ), were proposed independently by Naser [26], Nono [19,20], Shapiro and Vasilevsky [32,33]. More information about the importance of the structural sets can be found in [14,23,12,8,1,2,7]. The structural set ψ θ := {i, ie iθ j, e iθ j}, for 0 θ 2π fixed and its associated operator…”