English
If h is injective and the localization maps are compatible, then the induced map ĥ is injective.
Русский
Если h инъективно и локализационные отображения совместимы, тогда индукцированное отображение ĥ инъективно.
LaTeX
$$$$ \\text{Injective } h \\Rightarrow \\text{Injective } (\\text{map } S f g h) $$$$
Lean4
@[simp]
theorem map_injective (h : M →ₗ[R] N) (h_inj : Function.Injective h) : Function.Injective (map S f g h) :=
by
intro x y
obtain ⟨⟨x, s⟩, rfl⟩ := IsLocalizedModule.mk'_surjective S f x
obtain ⟨⟨y, t⟩, rfl⟩ := IsLocalizedModule.mk'_surjective S f y
simp only [Function.uncurry_apply_pair, map_mk', mk'_eq_mk'_iff, Subtype.exists, Submonoid.mk_smul, exists_prop,
forall_exists_index, and_imp]
intro c hc e
exact ⟨c, hc, h_inj (by simpa)⟩