Commit 2026-03-23 18:23 5197eece
View on Github →feat(Analysis/Normed/Module/WeakDual): register bornology and boundedness API (#36332)
Description
This PR registers Bornology instance and introduces a boundedness API as discussed on Zulip.
Main additions
WeakDual.instBornology: Bornology instance onWeakDual 𝕜 Einherited fromStrongDual 𝕜 EviainferInstanceAs. This makesIsBoundedavailable directly on weak dual sets, where boundedness means operator-norm boundedness.isBounded_iff_isVonNBounded: For normed spaces overℝorℂ, norm-boundedness and weak-* von Neumann boundedness coincide (via Banach–Steinhaus).isBounded_polarandisBounded_closedBall: Standalone lemmas replacing repeated inlineisBounded_toStrongDual_preimage_iff_isBounded.mpr ...patterns.- Simp lemmas:
isBounded_toStrongDual_preimage_iff_isBoundedandisBounded_toWeakDual_preimage_iff_isBoundedfor translating between weak and strong dual boundedness.
API simplification
The existing lemmas isClosed_image_coe_of_bounded_of_closed, isCompact_of_bounded_of_closed, and isSeqCompact_of_isBounded_of_isClosed now take IsBounded s directly instead of the more verbose IsBounded (StrongDual.toWeakDual ⁻¹' s), since the two are definitionally equal with the new bornology instance.
Minor changes
- Replaced
grindtactic usage with explicit term - Fixed deprecation dates from 2024-11-19 to 2025-11-19
- Renamed local variable
FtoEfor consistency with the rest of the file - Added comprehensive module and declaration docstrings