English
A hom between extensions f: P.Hom P' induces an R-algebra homomorphism f.toAlgHom from P.Ring to P'.Ring.
Русский
Гомоморфизм между расширениями f: P.Hom P' индуцирует R-алгебра-гомоморфизм f.toAlgHom: P.Ring → P'.Ring.
LaTeX
$$$f:\\mathrm{Hom}(P,P')\\Rightarrow f^{\\mathrm{toAlgHom}}:\\ P.Ring \\to_{R} P'.Ring$$$
Lean4
/-- A hom between extensions as an algebra homomorphism. -/
noncomputable def toAlgHom [Algebra R S'] [IsScalarTower R R' S'] (f : Hom P P') : P.Ring →ₐ[R] P'.Ring
where
__ := f.toRingHom
commutes' := by simp [← IsScalarTower.algebraMap_apply]