These formulas were called "general Lorentz transformation without rotation" by Christian Møller (1952), who in addition gave an even more general Lorentz transformation in which the Cartesian axes have different orientations, using a rotation operator D . In this case, v′ = (v′ x, v′ y, v′ z) is not equal to - v = (-v x, -v y, -v z), but the relation v ′ = − − D v holds instead, with the result