AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.IsRegularLocalRing_quotient_span_singleton_map_of_leftInverse_of_irreducible.SecSmooth.map_maximalIdeal_le_of_surjective
Source context 6 commands
Surrounding namespaces, section variables, and local commands at this declaration.
section ProofImplementation
namespace AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs
namespace IsRegularLocalRing_quotient_span_singleton_map_of_leftInverse_of_irreducible
open IsLocalRing
namespace SecSmooth
open IsLocalRingLean source · statement
theorem map_maximalIdeal_le_of_surjective {R A : Type*} [CommRing R] [IsLocalRing R] [CommRing A]
[IsLocalRing A]
(s : R →+* A) (hs : Function.Surjective s) : (maximalIdeal R).map s ≤ maximalIdeal A