English
The map fromOpenSubsetsGlue is injective on open cover data, i.e., different elements yield different glued points.
Русский
Отображение fromOpenSubsetsGlue инъективно: разные элементы дают разные точки склейки.
LaTeX
$$fromOpenSubsetsGlue is injective$$
Lean4
theorem fromOpenSubsetsGlue_injective : Function.Injective (fromOpenSubsetsGlue U) :=
by
intro x y e
obtain ⟨i, ⟨x, hx⟩, rfl⟩ := (ofOpenSubsets U).ι_jointly_surjective x
obtain ⟨j, ⟨y, hy⟩, rfl⟩ := (ofOpenSubsets U).ι_jointly_surjective y
rw [ι_fromOpenSubsetsGlue_apply, ι_fromOpenSubsetsGlue_apply] at e
subst e
rw [(ofOpenSubsets U).ι_eq_iff_rel]
exact ⟨⟨⟨x, hx⟩, hy⟩, rfl, rfl⟩