4. Uniform continuity versus continuity, detour to examples

Uniform continuity of f on A versus continuity of f in a point of A, where A is a nonempty subset of R, or of a metric space X (note typo for A in X).

NB Unless f is given by some formula or construction you are usually in the dark about how delta depends on epsilon.That's why we like Lipschitz continuous functions so much.