“…A further question we ask is : does the C 1 or C 1,β regularity holds, as in the case of the classical pLaplacian, [18], [12]? A first step would consist in proving the C 1 regularity when the right hand side is zero and then deduce from it the case f = 0 by methods as in [15], [3], but even in the case f ≡ 0 i have no intuition about the truthfullness of this result. The usual methods in the theory of viscosity solutions, ( [8], [17]), cannot directly be applied to the present case, one of the key argument of their proofs being the uniform ellipticity of the operator.…”