Recall that the set P(X) is called the power set of X; and, if A and B are sets, then A∪B is called the union of A and B and A∩B is called the inter...Recall that the set P(X) is called the power set of X; and, if A and B are sets, then A∪B is called the union of A and B and A∩B is called the intersection of A and B.
We now begin the process of abstraction. We will do this in stages, beginning with the concept of a field. First, we need to formally define some familiar sets of numbers.