English
The proof-theoretic version of tensorEquivMul asserts injectivity and surjectivity of the mulMap' induced isomorphism on I ⊗ J → I * J.
Русский
Версия доказательства для tensorEquivMul утверждает инъективность и сюръективность отображения mulMap' между I ⊗ J и I * J.
LaTeX
$$$ (Function.Injective (LinearMap.instFunLike.coe (I.val.mulMap' J.val))) \\land (Function.Surjective (LinearMap.instFunLike.coe (I.val.mulMap' J.val))). $$$
Lean4
instance instCharP (p : ℕ) [h : CharP R p] : CharP R[X] p :=
let ⟨h⟩ := h
⟨fun n => by rw [← map_natCast C, ← C_0, C_inj, h]⟩