

Since a sequence in a metric space (X d) is a function from N into X. De nition: A subset Sof a metric space (X d) is bounded if 9x 2X M2R : 8x2S: d(x x ) 5M: A function f: D(X d) is bounded if its image f(D) is a bounded set. Cauchy Sequences and Completeness of Spaces. distance function in a metric space, we can extend these de nitions from normed vector spaces to general metric spaces.

A sequence (xn) in a metric space (X,d) is called cofinally. An interactive introduction to mathematical analysis. Contraction mappings and the contraction mapping principle will also be explored. Thereby we get a generalization of Cauchy sequences, precisely defined as follows. Proof: Consider the collection of all Cauchy sequences in X. On decreasing nested sequences of non-empty compact setsĬantor's intersection theorem refers to two closely related theorems in general topology and real analysis, named after Georg Cantor, about intersections of decreasing nested sequences of non-empty compact sets. A Cauchy sequence is a sequence of points in a metric space that satisfies the following condition: for any positive number epsilon, there exists a natural number N such that the distance between. A sequence (xn) of elements of a metric space (X, ) is called a Cauchy sequence if, given any > 0, there exists N. a metric space X (X, d) which is complete and such that X is sometric to a dense subset of X.
