xorxes:
<But it can also be that the mass is somehow less than the sum of
it's elements, when there is some kind of overlap among the elements.
It all depends on how you define the sum, of course.>
"Sum" is left pretty vague as a promissory note to fill it in, though
xorxes
seems sure that it cannot be. I was trying to think of a case of the sort
he
suggests here, but nothing natural came to mind -- orverlapping is not
something things do well. It works nicely with sets, of course, but masses
of sets are not very pleasant to contemplate.