There is an explanation oed6 math in Sunray's site.
For some reason though I can read the whole document but when it get's to the part of giving the formula (p(n)= ...) it is left blank. Maybe it's a problem with open office...
Also I found some interesting discussion in the old ibm
strategy forums.
It looks like it's about dominions PPP. It also seems to back Truper's explanation.
I admit I'm completely
puzzled
here.