Module

ModuleBaseChangeHomExt.lean

Nyll.SchemeTheory.RingTheory.Descent.ModuleBaseChangeHomExt
2 declarations indexed from sourceView source ↗

Extensionality for homomorphisms between base-changed modules

Maps between tensor extensions are determined on elements 1 ⊗ m, and maps between localized modules are determined on fractions with denominator one. These are the two componentwise extensionality lemmas used by mixed formal gluing.

Declarations

EtaleFundamentalGroups.tensorProduct_linearMap_ext_of_one_tmul

An S-linear map between scalar extensions is determined by its values on the canonical generators 1 ⊗ m.

Source context 8 commands

Surrounding namespaces, section variables, and local commands at this declaration.

noncomputable section
namespace EtaleFundamentalGroups
open scoped TensorProduct
universe u v w w'
variable {R : Type u} [CommRing R]
variable {S : Type v} [CommRing S] [Algebra R S]
variable {M : Type w} [AddCommGroup M] [Module R M]
variable {N : Type w'} [AddCommGroup N] [Module R N]
theorem tensorProduct_linearMap_ext_of_one_tmul
    {F G : (S ⊗[R] M) →ₗ[S] (S ⊗[R] N)}
    (h : ∀ m : M, F (1 ⊗ₜ[R] m) = G (1 ⊗ₜ[R] m)) :
    F = G
EtaleFundamentalGroups.localizedModule_linearMap_ext_of_mk_one

A linear map between localized modules is determined by the images of the source elements with denominator one.

Source context 8 commands

Surrounding namespaces, section variables, and local commands at this declaration.

noncomputable section
namespace EtaleFundamentalGroups
open scoped TensorProduct
universe u v w w'
variable {R : Type u} [CommRing R]
variable {S : Type v} [CommRing S] [Algebra R S]
variable {M : Type w} [AddCommGroup M] [Module R M]
variable {N : Type w'} [AddCommGroup N] [Module R N]
theorem localizedModule_linearMap_ext_of_mk_one
    (T : Submonoid R)
    {F G : LocalizedModule T M →ₗ[Localization T]
      LocalizedModule T N}
    (h : ∀ m : M,
      F (LocalizedModule.mk m 1) = G (LocalizedModule.mk m 1)) :
    F = G