Original sentence: However, present day understanding of decoherence does not allow a completely precise, self contained way to say when the two branches have decohered/"do not interact", and hence many worlds interpretation remains vague.The many worlds interpretation is very vague about the ways to determine when splitting happens, and nowadays usually the criterion is that the two branches have decohered.This is the main objection opponents of this interpretation rise, saying that it is not clear what is precisely meant by branching, and point to lack of self contained criterion specifying branching to be described
Edited sentence: The flip side of quantum suicide is quantum immortality