[en] It is shown that, within the author's generally covariant field theory, the decay of the muon to an electron and 2γ is forbidden. This follows from earlier results of this field theory in which the state of 2γ in this process must identify with an exact solution for the coupled, nonlinear spinor equations for the electron-positron, corresponding to zero energy (relative to the asymptotically free state of energy 2m), zero momentum and zero angular momentum. In view of the conservation of energy-momentum, it then follows that the muon cannot decay to e^+- + 2γ