English
The forgetful map from Subalgebra to Submodule is an order-embedding.
Русский
Отображение от Subalgebra к Submodule является внедрением порядка.
LaTeX
$$$$ \\text{toSubmodule} : \\text{Subalgebra } R A \\hookrightarrow \\text{Submodule } R A $$$$
Lean4
/-- The forgetful map from `Subalgebra` to `Submodule` as an `OrderEmbedding` -/
def toSubmodule : Subalgebra R A ↪o Submodule R A
where
toEmbedding :=
{ toFun := fun S =>
{ S with
carrier := S
smul_mem' := fun c {x} hx ↦ (Algebra.smul_def c x).symm ▸ mul_mem (S.range_le ⟨c, rfl⟩) hx }
inj' := fun _ _ h ↦ ext fun x ↦ SetLike.ext_iff.mp h x }
map_rel_iff' := SetLike.coe_subset_coe.symm.trans SetLike.coe_subset_coe