power set

[jankapunkt]

There needs to be a boolean operation on instances of Sets that allow the following:

What you say: "The power set of A" or "The set of subsets of A"
What you type: Set.powerSet(A)
note: I have always heard people always say "the power set of A", but never "the power of A". Hence, I believe truncating the function name to only "power" would cause confusion, since the term "power" can mean so many different things.

[jankapunkt]

First we need to clarify naming conventions as stated in #22