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Mathlib.Analysis.Normed.Operator.CompleteCodomain

Completeness of spaces of linear and multilinear maps #

If E is a nontrivial normed space over a nontrivially normed field 𝕜, and E has a separating dual, then for any normed space F, the completeness of the space of continuous linear maps from E to F is equivalent to the completeness of F.

A similar statement holds for spaces of continuous multilinear maps

If a space of linear maps from E to F is complete, and E is nontrivial, then F is complete.

theorem SeparatingDual.completeSpace_of_completeSpace_continuousMultilinearMap (𝕜 : Type u_1) (F : Type u_3) [NontriviallyNormedField 𝕜] [NormedAddCommGroup F] [NormedSpace 𝕜 F] {ι : Type u_4} [Finite ι] {M : ιType u_5} [(i : ι) → NormedAddCommGroup (M i)] [(i : ι) → NormedSpace 𝕜 (M i)] [∀ (i : ι), SeparatingDual 𝕜 (M i)] [CompleteSpace (ContinuousMultilinearMap 𝕜 M F)] {m : (i : ι) → M i} (hm : ∀ (i : ι), m i 0) :

If a space of multilinear maps from Π i, E i to F is complete, and each E i has a nonzero element, then F is complete.

theorem SeparatingDual.completeSpace_continuousMultilinearMap_iff (𝕜 : Type u_1) (F : Type u_3) [NontriviallyNormedField 𝕜] [NormedAddCommGroup F] [NormedSpace 𝕜 F] {ι : Type u_4} [Finite ι] {M : ιType u_5} [(i : ι) → NormedAddCommGroup (M i)] [(i : ι) → NormedSpace 𝕜 (M i)] [∀ (i : ι), SeparatingDual 𝕜 (M i)] {m : (i : ι) → M i} (hm : ∀ (i : ι), m i 0) :