English
A variant of the rank bound under injective maps producing a monotone inequality.
Русский
Вариант границы ранга под инъективными отображениями, дающий монотонное неравенство.
LaTeX
$$$\operatorname{rank}_R(M) \le \operatorname{rank}_{R'}(M')$$$
Lean4
/-- The same-universe version of `lift_rank_le_of_injective_injective`. -/
theorem rank_le_of_injective_injectiveₛ (i : R' → R) (j : M →+ M₁) (hi : Injective i) (hj : Injective j)
(hc : ∀ (r : R') (m : M), j (i r • m) = r • j m) : Module.rank R M ≤ Module.rank R' M₁ := by
simpa only [lift_id] using lift_rank_le_of_injective_injectiveₛ i j hi hj hc