English
The von Neumann bornology equals the metric bornology on a normed space.
Русский
Фон Неймана борология равна метрической борологии в нормированном пространстве.
LaTeX
$$$\\operatorname{vonNBornology}_{\\mathbb{k}}(E) = \\mathsf{toBornology}(\\text{Metric})$$$
Lean4
/-- In a normed space, the von Neumann bornology (`Bornology.vonNBornology`) is equal to the
metric bornology. -/
theorem vonNBornology_eq : Bornology.vonNBornology 𝕜 E = PseudoMetricSpace.toBornology :=
by
rw [Bornology.ext_iff_isBounded]
intro s
rw [Bornology.isBounded_iff_isVonNBounded]
exact isVonNBounded_iff _