# Bounding point

In functional analysis, a branch of mathematics, a bounding point of a subset of vector space is a conceptual extension of the boundary of the set.

## Definition

Let ${\displaystyle A\subset X}$ for some vector space ${\displaystyle X}$. Then ${\displaystyle x\in X}$ is a bounding point for ${\displaystyle A}$ if it is neither an internal point for ${\displaystyle A}$ nor its complement.[1]

## References

1. Henry Hermes; Joseph P. La Salle (1969). Functional Analysis & Time Optimal Control. Academic Press. p. 8. ISBN 9780123426505.