Thread: Partition of a set

The question is to determine whether is a partition of the set .

and , where .

I understand what it means to be a partition, but I'm not sure what , or particularly, means.

Does this mean ? Where I just find any real number pair so that their absolute values are equal?

Are those sets in disjoint? Non-empty? Does their union equal the whole set (in this case, )? If so, then is a partition of

--------------------------
The only potentially confusing thing here is that the original definition of had redundancies - two different names for the same set - and so that might seem to make it not a partition. However, a set with redundant (even if differently named) elements is the same as the set with unique elements.

i.e. If a = -2, b = -2, then U = {a, b} = { -2, -2 } = { -2 } = { a }.

Likewise: If A = {5, -2}, B = {5, -2}, then V = {A, B} = { {5,-2}, {5,-2} } = { {5,-2} } = { A }.