English
The homogeneousSubmodule construction forms a gradedMonoid structure; the grading is compatible with multiplication.
Русский
Конструкция однородных подмодулей образует градаированный моноид; градация совместима с умножением.
LaTeX
$$gradedMonoid : SetLike.GradedMonoid (homogeneousSubmodule σ R)$$
Lean4
/-- The canonical algebra isomorphism from `MvPolynomial Unit R` quotiented by
`C r * X () - 1` to the localization of `R` away from `r`. -/
noncomputable def mvPolynomialQuotientEquiv : ((MvPolynomial Unit R) ⧸ Ideal.span {C r * X () - 1}) ≃ₐ[R] S
where
toFun := auxHom S r
invFun := auxInv S r
left_inv x := by simpa using congrFun (congrArg DFunLike.coe <| auxInv_auxHom S r) x
right_inv s := by simpa using congrFun (congrArg DFunLike.coe <| auxHom_auxInv S r) s
map_mul' := by simp
map_add' := by simp
commutes' := by simp