Definition:Bounded Mapping/Metric Space

This page is about Bounded Mapping in the context of Metric Space. For other uses, see Bounded.

Definition

Let $M$ be a metric space.

Let $f: X \to M$ be a mapping from any set $X$ into $M$.

Then $f$ is a bounded mapping if and only if $f \sqbrk X$ is bounded in $M$.

Warning

From Real Number Line is Metric Space, we can in theory consider defining boundedness on a real-valued function in terms of boundedness of a mapping into a metric space.

However, as a metric space is itself defined in terms of a real-valued function in the first place, this concept can be criticised as being a circular definition.

Sources

• 1975: W.A. Sutherland: Introduction to Metric and Topological Spaces ... (previous) ... (next): $2$: Continuity generalized: metric spaces: $2.2$: Examples: Definition $2.2.14$