In decoherence.. it is said that it is in an improper mixed FAPP (for all purposes) which is the same as collapse. Are you saying that decoherence is deterministic and not random (probabilities)? Random or probabilities only occured in proper mix? Why. Is it not possible to calculate exactly the wavelets and waveforms of the wave functions to tell how exactly the decohering interference occur and from there determine why it is in certain state (deterministic)? Why not?