English
The nonunital isometric continuous functional calculus instance extends to IsSelfAdjoint in nonunital C*-algebras.
Русский
Непользовательное изометрическое непрерывное функциональное исчисление распространяется на IsSelfAdjoint в неединичных C*-алгебрах.
LaTeX
$$NonUnitalIsometricContinuousFunctionalCalculus ℂ A IsSelfAdjoint$$
Lean4
instance instNonUnitalIsometricContinuousFunctionalCalculus :
NonUnitalIsometricContinuousFunctionalCalculus ℂ A IsStarNormal where
isometric a
ha := by
refine AddMonoidHomClass.isometry_of_norm _ fun f ↦ ?_
rw [← norm_inr (𝕜 := ℂ), ← inrNonUnitalStarAlgHom_apply, ← NonUnitalStarAlgHom.comp_apply,
inr_comp_cfcₙHom_eq_cfcₙAux a, cfcₙAux]
simp only [NonUnitalStarAlgHom.comp_assoc, NonUnitalStarAlgHom.comp_apply, toContinuousMapHom_apply,
NonUnitalStarAlgHom.coe_coe]
rw [norm_cfcHom (a : Unitization ℂ A), StarAlgEquiv.norm_map]
rfl