Spaces of functions and sets
Share

# Spaces of functions and sets

• ·

Written in English

• Topology.,
• Set theory.

## Book details:

Edition Notes

Classifications The Physical Object Statement by R.B. Sher. Series Monographs in undergraduate mathematics -- v.1 Contributions Guilford College., Conference on Undergraduate Mathematics (1975 : Guilford College) LC Classifications QA611 .S54 Pagination 40 p. : Number of Pages 40 Open Library OL14810565M

A metric space is a set Xtogether with a metric don it, and we will use the notation (X;d) for a metric space. Often, if the metric dis clear from context, we will simply denote the metric space (X;d) by Xitself. Example 1. The set of real numbers R with the function d(x;y) = jx yjis a metric space. More. Equicontinuity between metric spaces. Let X and Y be two metric spaces, and F a family of functions from X to shall denote by d the respective metrics of these spaces.. The family F is equicontinuous at a point x 0 ∈ X if for every ε > 0, there exists a δ > 0 such that d(ƒ(x 0), ƒ(x)). A metric space is a non-empty set equi pped with structure determined by a well-defin ed notion of distan ce. The term ‘m etric’ i s d erived from the word metor (measur e).   The essential uniqueness of density functions can fail if the positive measure space $$(S, \ms S, \mu)$$ is not $$\sigma$$-finite. A simple example is given below. Our next result answers the question of when a measure has a density function with respect to $$\mu$$, and is the fundamental theorem of this section.
7 Functions of bounded variation and absolutely continuous functions Measure Spaces Algebras and σ–algebras of sets Notation and preliminaries We shall denote by X a nonempty set, by P(X) the set of all parts (i.e., subsets) of X, and by ∅ the empty set. Let Aand Bbe sets. A function ffrom Ato Bis to be thought of as a rule which assigns to every element aof the set Aan element f(a) of the set B. The set Ais called the domain of f and Bthe codomain (or target) of f. We use the notation ‘f:A→ B’ (read ‘f, from Ato B’) to mean that f is a function with domain Aand codomain B.   We can now discuss various vector spaces of functions. First, we know from our previous work with measure spaces, that the set $$\mathscr{V}$$ of all measurable functions $$f: S \to \R$$ is a vector space under our standard (pointwise) definitions of sum and scalar multiple. The spaces we are studying in this section are subspaces. Introduction To Mathematical Analysis John E. Hutchinson Revised by Richard J. Loy /6/7 Department of Mathematics School of Mathematical Sciences.