English
The same-universe version of rank equality under algebra equivalences asserts equality of ranks.
Русский
Та же вселенная версия равенства рангов при эквивалентностях алгебр утверждает равенство рангов.
LaTeX
$$$\operatorname{rank}_R S = \operatorname{rank}_{R'} S'$$$
Lean4
/-- The same-universe version of `Algebra.lift_rank_eq_of_equiv_equiv`. -/
theorem rank_eq_of_equiv_equiv (i : R ≃+* R') (j : S ≃+* S')
(hc : (algebraMap R' S').comp i.toRingHom = j.toRingHom.comp (algebraMap R S)) :
Module.rank R S = Module.rank R' S' := by simpa only [lift_id] using lift_rank_eq_of_equiv_equiv i j hc