English
Converse to the previous transfer: given h and h', and e: T ≃ₐ[R] U, h.algEquiv (h'.ofAlgEquiv e) equals (h.algEquiv h').trans e.
Русский
Обратное преобразование: дадим e, получаем равенство изоморфизмов.
LaTeX
$$$h.algEquiv (h'.ofAlgEquiv e) = (h.algEquiv h').trans e$$$
Lean4
@[simp]
theorem algEquiv_ofAlgEquiv {U : Type*} [Ring U] [Algebra R U] (e : T ≃ₐ[R] U) :
h.algEquiv (h'.ofAlgEquiv e) = (h.algEquiv h').trans e :=
by
ext a
simp [algEquiv_def, AlgEquiv.trans_apply, adjoinRootAlgEquiv_apply_eq_map, ofAlgEquiv_map_apply]