English
The vanishing ideal of the image of a set V under the map pointToPoint equals the vanishing ideal of V.
Русский
Нулевая идеал образа множества V под отображением pointToPoint равен нулевой идеалV.
LaTeX
$$PrimeSpectrum.vanishingIdeal (pointToPoint '' V) = MvPolynomial.vanishingIdeal(k, V)$$
Lean4
@[simp]
theorem vanishingIdeal_pointToPoint (V : Set (σ → K)) :
PrimeSpectrum.vanishingIdeal (pointToPoint '' V) = MvPolynomial.vanishingIdeal k V :=
le_antisymm
(fun _ hp x hx =>
(((PrimeSpectrum.mem_vanishingIdeal _ _).1 hp) ⟨vanishingIdeal k { x }, by infer_instance⟩ (⟨x, hx, rfl⟩ : _)) x
rfl)
fun _ hp =>
(PrimeSpectrum.mem_vanishingIdeal _ _).2 fun _ hI =>
let ⟨x, hx⟩ := hI
hx.2 ▸ fun _ hx' => (Set.mem_singleton_iff.1 hx').symm ▸ hp x hx.1