This work is dedicated to study the pseudodifferential operator (π·πΌπ1,π2π)(π₯)=ββ«βππξβπΌπ1,π2(π¦)[π(π₯+π¦)βπ(π₯)]πππ¦, which can be seen as a generalization of Taibleson operator; here ξπΌπ1,π2(π₯)=max{βπ₯βπ1π, βπ₯βπ2π}πΌ. We show that semi-linear Cauchy problem is well-posed in ππ [a Banach space containing functions that do not belong to πΏ1(βππ)], assuming that semi-linear part f is a Lipschitz function. We associate to the corresponding homogeneous problem a Markov process, which is indeed a Feller process. Finally, we study the first passage time problem.