English
The composition of two inclusions corresponds to the inclusion with the transitive composition of the containment relations.
Русский
Состав включений эквивалентен включению, соответствующему транзитивному включению.
LaTeX
$$inclusion_inclusion : inclusion htu (inclusion hst x) = inclusion (le_trans hst htu) x$$
Lean4
/-- The map `S → T` when `S` is a non-unital subalgebra contained in the non-unital subalgebra `T`.
This is the non-unital subalgebra version of `Submodule.inclusion`, or `Subring.inclusion` -/
def inclusion {S T : NonUnitalSubalgebra R A} (h : S ≤ T) : S →ₙₐ[R] T
where
toFun := Set.inclusion h
map_add' _ _ := rfl
map_mul' _ _ := rfl
map_zero' := rfl
map_smul' _ _ := rfl