English
If Frobenius map Frobenius_{R,p} is injective for a ring R, then pNilradical R p = ⊥.
Русский
Если отображение Фробениуса Frobenius_{R,p} insulin инъективно, то pNilradical R p = ⊥.
LaTeX
$$$$ \\text{If } \\operatorname{Injective}(\\mathrm{frobenius}_{R,p}) \\text{ then } pNilradical(R,p)=\\bot. $$$$
Lean4
theorem pNilradical_eq_bot_of_frobenius_inj (R : Type*) [CommSemiring R] (p : ℕ) [ExpChar R p]
(h : Function.Injective (frobenius R p)) : pNilradical R p = ⊥ :=
bot_unique fun x ↦ by
rw [mem_pNilradical, Ideal.mem_bot]
exact fun ⟨n, _⟩ ↦ h.iterate n (by rwa [← coe_iterateFrobenius, map_zero])