Sets of π-extent in π-dimensional space
Ralph Jeffery Β· Transactions of the American Mathematical Society Β· 1933
The number of ways of selecting each Bn is more than countable, and no rule is given for any particular choice. Consequently it is impossible to say of every point of the domain D whether or not it belongs to the set AT. This amounts to saying that the set AT is not well-defined. It is possible to replace the set A by a set A' which is effectively defined. Let B be the complement of A on D. Let Wk be a sequence of cells with a point b of B as center, and with equal side lengths tending to zero as k increases. Let IA*AWk p(b, Wk) =