打算
发表于 2025-3-30 08:20:03
Normed and Function Spaces,cause a metric space need not be an . or even a .. Any (nonempty) subset of a metric space is again a metric space with the metric it borrows from the ambient space. Thus, curves and surfaces in the Euclidean space ℝ. are metric spaces but are almost never . of ℝ.. Even straight lines and planes are