English
A reduced-to-separated partial map f is equivalent to a morphism g if and only if f.hom = f.domain.ι ≫ g.
Русский
Частичная карта f эквивалентна морфизму g тогда и только тогда, когда f.hom = f.domain.ι ∘ g.
LaTeX
$$$f\equiv g.f \,?\;f\hom = f.domain.ι \circ g$$$
Lean4
/-- A partial map from a reduced scheme to a separated scheme is equivalent to a morphism
if and only if it is equal to the restriction of the morphism. -/
theorem equiv_toPartialMap_iff_of_isSeparated [X.Over S] [Y.Over S] [IsReduced X] [IsSeparated (Y ↘ S)]
{f : X.PartialMap Y} {g : X ⟶ Y} [f.IsOver S] [g.IsOver S] : f.equiv g.toPartialMap ↔ f.hom = f.domain.ι ≫ g :=
by
rw [equiv_iff_of_isSeparated (S := S), ← cancel_epi (X.isoOfEq (inf_top_eq f.domain)).hom]
simp
rfl