English
For any t in the spectrum, the zero locus of the vanishing ideal of t equals the closure of t.
Русский
Для любого множества t спектра нулевая локус идеала исчезновения t равна замыканию t.
LaTeX
$$$\\mathrm{zeroLocus}(\\mathrm{vanishingIdeal}(t)) = \\mathrm{closure}(t)$$$
Lean4
theorem zeroLocus_vanishingIdeal_eq_closure (t : Set (PrimeSpectrum R)) :
zeroLocus (vanishingIdeal t : Set R) = closure t :=
by
rcases isClosed_iff_zeroLocus (closure t) |>.mp isClosed_closure with ⟨I, hI⟩
rw [subset_antisymm_iff, (isClosed_zeroLocus _).closure_subset_iff, hI, subset_zeroLocus_iff_subset_vanishingIdeal,
(gc R).u_l_u_eq_u, ← subset_zeroLocus_iff_subset_vanishingIdeal, ← hI]
exact ⟨subset_closure, subset_zeroLocus_vanishingIdeal t⟩