Topic: Metric Spaces and Open Balls

Restricting a Metric to a Subset

Radius Changes and Ball Inclusions

Open Balls and Their Centers and Radii

Metric Openness Through Local Balls

Metric Axiom Checks on Finite Sets

Hamming Distance on Finite Strings

Graph Distance as a Metric

Euclidean Distance in Rn

Computing Balls in Euclidean, Taxicab, and Sup Metrics

Balls in Discrete and Ultrametric Spaces