The converse is also true, but the decomposition of a finite general Lorentz transformation into such factors is nontrivial. In particular, e − − ζ ζ ⋅ ⋅ K + θ θ ⋅ ⋅ J ≠ ≠ e − − ζ ζ ⋅ ⋅ K e θ θ ⋅ ⋅ J , because the generators do not commute. For a description of how to find the factors of a general Lorentz transformation in terms of a boost and a rotation in principle (this usually does not yield an intelligible expression in terms of generators J and K), see Wigner rotation. If, on the other hand, the decomposition is given in terms of the generators, and one wants to find the product in terms of the generators, then the Baker–Campbell–Hausdorff formula applies.