English
Similarly, the span target version yields an equivalence with its finite-span-target counterpart for localization properties.
Русский
Аналогично, версия со SpanTarget эквивалентна своей конечной версии для локализаций.
LaTeX
$$$\\forall P,\\; \\RingHom.OfLocalizationSpanTarget P \\;\\Leftrightarrow \\RingHom.OfLocalizationFiniteSpanTarget P$$$
Lean4
theorem ofLocalizationSpanTarget_iff_finite :
RingHom.OfLocalizationSpanTarget @P ↔ RingHom.OfLocalizationFiniteSpanTarget @P :=
by
delta RingHom.OfLocalizationSpanTarget RingHom.OfLocalizationFiniteSpanTarget
apply forall₅_congr
intros
constructor
· intro h s; exact h s
· intro h s hs hs'
obtain ⟨s', h₁, h₂⟩ := (Ideal.span_eq_top_iff_finite s).mp hs
exact h s' h₂ fun x => hs' ⟨_, h₁ x.prop⟩