English
For any submodule p of M, the image of p under the injection inl into M × M₂ equals the product p × ⊥.
Русский
Для подмодуля p ⊆ M образ под инъекцией inl в M × M₂ равен p × ⊥.
LaTeX
$$$\\mathrm{map}(\\mathrm{inl}\\, R\\, M\\, M_2)(p) = p \\times \\bot$$$
Lean4
@[simp]
theorem map_inl : p.map (inl R M M₂) = prod p ⊥ := by
ext ⟨x, y⟩
simp only [and_left_comm, eq_comm, mem_map, Prod.mk_inj, inl_apply, mem_bot, exists_eq_left', mem_prod]