English
For AlgHom f and g, the composition of maps equals the map of the composed AlgHom.
Русский
Для AlgHom f и g композиция отображений равна отображению композиции AlgHom.
LaTeX
$$$ (I.map f).map g = I.map (g \circ f) $$$
Lean4
theorem map_mapₐ {R A B C : Type*} [CommSemiring R] [Semiring A] [Algebra R A] [Semiring B] [Algebra R B] [Semiring C]
[Algebra R C] {I : Ideal A} (f : A →ₐ[R] B) (g : B →ₐ[R] C) : (I.map f).map g = I.map (g.comp f) :=
I.map_map f.toRingHom g.toRingHom