English
If Y is prespectral and f : X → Y is inducing and IsSpectralMap, then X is prespectral.
Русский
Если Y prespectral, а f: X → Y индуцирующее и спектральное отображение, то X prespectral.
LaTeX
$$$[\\mathrm{PrespectralSpace}(Y)] \\land (f: X\\to Y) \\text{ inducing} \\land (f \\text{ isSpectralMap}) \\Rightarrow \\mathrm{PrespectralSpace}(X)$$$
Lean4
theorem of_isInducing [PrespectralSpace Y] (f : X → Y) (hf : IsInducing f) (hf' : IsSpectralMap f) :
PrespectralSpace X :=
.of_isTopologicalBasis (PrespectralSpace.isTopologicalBasis.isInducing hf)
(by
simp only [Set.mem_image, Set.mem_setOf_eq, forall_exists_index, and_imp]
rintro _ U h₁ h₂ rfl
exact hf'.isCompact_preimage_of_isOpen h₁ h₂)