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MathlibAnnex.Analysis.CStarAlgebra.Representation.cardinalMk_le_continuum_of_injective

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MathlibAnnex/Analysis/CStarAlgebra/Representation/SeparableCardinality.lean · lines 22–26

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1import MathlibAnnex.Analysis.Normed.Operator.Cardinality
2import MathlibAnnex.Analysis.CStarAlgebra.NonUnital.Representation
3
4/-! # Cardinal upper bounds for faithfully separably represented algebras -/
5set_option autoImplicit false
6open scoped Cardinal
7namespace MathlibAnnex.Analysis.CStarAlgebra
8universe u v
9variable {A : Type u} {H : Type v}
10variable [NormedAddCommGroup H] [InnerProductSpace ℂ H] [CompleteSpace H]
11variable [TopologicalSpace.SeparableSpace H]
12
13/-- A faithful ordinary representation on a separable Hilbert space bounds
14the cardinality of the possibly nonunital source algebra by the continuum. -/
15theorem NonUnitalCStarRepresentation.cardinalMk_le_continuum_of_injective
16    [NonUnitalCStarAlgebra A] (pi : NonUnitalCStarRepresentation A H)
17    (hpi : Function.Injective pi) : #A ≤ Cardinal.continuum :=
18  MathlibAnnex.Topology.cardinalMk_le_continuum_of_injective pi hpi
19    (MathlibAnnex.cardinalMk_continuousLinearMap_le_continuum H)
20
21/-- The unital counterpart of the faithful separable-representation bound. -/
22theorem Representation.cardinalMk_le_continuum_of_injective
23    [CStarAlgebra A] (pi : Representation A H) (hpi : Function.Injective pi) :
24    #A ≤ Cardinal.continuum :=
25  NonUnitalCStarRepresentation.cardinalMk_le_continuum_of_injective
26    pi.toNonUnitalStarAlgHom hpi
27
28end MathlibAnnex.Analysis.CStarAlgebra