Sets, complements and boundaries
A constructive approach to sets, their complements and their boundaries is presented. A constructive theorem on a point of a segment close to the set boundary in a Banach space is used. Brouwerian examples are used to show that the results are best possible. In particular the following questions are addressed: It is possible to compute the distance of any point of a set to its boundary if we can compute the distance of any point of the metric space to the set? If a point is bounded away from the complement of a set, can we show that it is in the set?
scientific article; zbMATH DE number 989748
scientific article