English
QuasispectrumRestricts a f is equivalent to SpectrumRestricts (Unitization.inr a) f.
Русский
QuasispectrumRestricts a f эквивалентно SpectrumRestricts (Unitization.inr a) f.
LaTeX
$$$ QuasispectrumRestricts a f \\iff SpectrumRestricts (Unitization.inr a) f $$$
Lean4
/-- The difference from `quasispectrumRestricts_iff_spectrumRestricts_inr` is that the
`Unitization` may be taken with respect to a different scalar field. -/
theorem quasispectrumRestricts_iff_spectrumRestricts_inr' {R S' A : Type*} (S : Type*) [Semifield R] [Semifield S']
[Field S] [NonUnitalRing A] [Module R A] [Module S' A] [Module S A] [IsScalarTower S A A] [SMulCommClass S A A]
[Algebra R S'] [Algebra S' S] [Algebra R S] [IsScalarTower S' S A] [IsScalarTower R S A] {a : A} {f : S' → R} :
QuasispectrumRestricts a f ↔ SpectrumRestricts (a : Unitization S A) f := by
simp only [quasispectrumRestricts_iff, SpectrumRestricts, Unitization.quasispectrum_inr_eq]