English
For any f: A →ₐ[R] B, the inclusion algebraMapSubmonoid A M is contained in the comap of algebraMapSubmonoid B M along f.
Русский
Для любого f: A →ₐ[R] B выполняется включение algebraMapSubmonoid A M ≤ comap(f.toRingHom) (algebraMapSubmonoid B M).
LaTeX
$$$ algebraMapSubmonoid A M ≤ (algebraMapSubmonoid B M).comap f.toRingHom $$$
Lean4
theorem algebraMapSubmonoid_le_comap (f : A →ₐ[R] B) :
algebraMapSubmonoid A M ≤ (algebraMapSubmonoid B M).comap f.toRingHom :=
by
rw [← algebraMapSubmonoid_map_eq M f]
exact Submonoid.le_comap_map (Algebra.algebraMapSubmonoid A M)