Suppose is a -ring. Suppose . How would we show that ?
We know that . Likewise, how would we show that and ? The former is the set of points that are in infinitely many . The latter is the set of points that are in all but a finite number of .
Suppose is a -ring. Suppose . How would we show that ?
We know that . Likewise, how would we show that and ? The former is the set of points that are in infinitely many . The latter is the set of points that are in all but a finite number of .