  We analyze the dependence of the squared amplitudes on the
rephasing-invariant CP-violating parameters of the lepton sector, involving
Majorana neutrinos, for various lepton-conserving and lepton-violating
processes. We analyze the conditions under which the CP-violating effects in
such processes vanish, in terms of the minimal set of rephasing invariants,
giving special attention to the dependence on the extra CP-violating parameters
that are due to the Majorana nature of the neutrinos.
