rapidly until today virtually every field of mathematics has felt its impact. Notions of the geometry of space, for example, have been completely revoluionized by the theory of sets. Also, the basic concepts in analysis,such as those of limit,function, continuity, derivative, an integral, are now most aptly described in terms of set-theory ideas. Most important, however, has been the opportuity for new mathematical developments undreamed of fifty years ago. Thus, in companionship with the new appreciation of postulational procedures in mathematics, abstract spaces have been born, general theories of dimension and measure have been created, and the branch of mathematics, called topology has undergone a spectacular growth. In short, under the influence of set theory, a considerable unification of traditional mathematics has occurred, and new mathematics has been creted at an explosive rate.
To illustrate the historical evolution to basic concepts, let us first consider notions of space and the geometry of a space and the These concepts have undergone marked changes since the day of the ancient Greeks.
the space was not thoughtof as a collection of points, but rather as a realm, or locus, in which objects could be freely moved about and compared with one another. from this point of view, the basic relation in geometry was that of congruence or superposability