Comment by jacb

Perhaps it's consistent with computation being done in many "parallel universes," but with heavily restricted communication - in this model it's almost trivial to parallelize work (flip a quantum coin, do A if heads else B), what's tough is making sure that you don't get parallelized along with the work (i.e. that you don't become entangled with the computation) and making sure there's a way to accumulate the parallel computation into something that's singly-readable and useful.