"Partially overlaping accumulates (e.g., an accumulate that updates a
complex number, while another concurrent accumlate updates the real
part of the the number) are erroneous. Also, are erroneous concurrent
accumulates to the same variable with distinct operations."
Do we want these to be erroneous or undefined? Erroneous means the
program can crash and burn. It seems to me we make no promise about
which parts of the update wind up in each part of the variable but
that some parts do wind up there.
Steve