Module

SubmoduleOverEquality.lean

Nyll.SchemeTheory.Modules.SubmoduleOverEquality
4 declarations indexed from sourceView source ↗

Exact restriction equalities for the finite-open induction

Equality on a slice gives equality of every actual section submodule below that slice. It is therefore inherited by smaller slices, and the native gluing has the exact prescribed restrictions on both opens.

Declarations

SheafOfModules.Submodule.obj_eq_of_over_eq

Exact equality on a slice identifies every section submodule below it.

Source context 5 commands

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

noncomputable section
universe v v₁ u₁ u
open CategoryTheory Opposite
namespace SheafOfModules.Submodule
variable {C : Type u₁} [Category.{v₁} C] {J : GrothendieckTopology C}
  {R : Sheaf J RingCat.{u}} {M : SheafOfModules.{v} R}
theorem obj_eq_of_over_eq {N P : M.Submodule} {U : C}
    (h : N.over U = P.over U) (V : C) (f : V ⟶ U) :
    N.toSubmodule.obj (op V) = P.toSubmodule.obj (op V)
SheafOfModules.Submodule.over_eq_of_over_eq

Literal equality of native submodules persists under further restriction.

Source context 5 commands

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

noncomputable section
universe v v₁ u₁ u
open CategoryTheory Opposite
namespace SheafOfModules.Submodule
variable {C : Type u₁} [Category.{v₁} C] {J : GrothendieckTopology C}
  {R : Sheaf J RingCat.{u}} {M : SheafOfModules.{v} R}
theorem over_eq_of_over_eq {N P : M.Submodule} {U V : C}
    (h : N.over V = P.over V) (f : U ⟶ V) : N.over U = P.over U
SheafOfModules.Submodule.glueOn_over_eq_left

The constructed gluing has exactly the first prescribed native restriction.

Source context 5 commands

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

noncomputable section
universe v v₁ u₁ u
open CategoryTheory Opposite
namespace SheafOfModules.Submodule
variable {C : Type u₁} [Category.{v₁} C] {J : GrothendieckTopology C}
  {R : Sheaf J RingCat.{u}} {M : SheafOfModules.{v} R}
theorem glueOn_over_eq_left (N P : M.Submodule) (U V : C)
    (h : ∀ (Z : C) (_a : Z ⟶ U) (_b : Z ⟶ V),
      N.toSubmodule.obj (op Z) = P.toSubmodule.obj (op Z)) :
    (glueOn N P U V).over U = N.over U
SheafOfModules.Submodule.glueOn_over_eq_right

The constructed gluing has exactly the second prescribed native restriction.

Source context 5 commands

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

noncomputable section
universe v v₁ u₁ u
open CategoryTheory Opposite
namespace SheafOfModules.Submodule
variable {C : Type u₁} [Category.{v₁} C] {J : GrothendieckTopology C}
  {R : Sheaf J RingCat.{u}} {M : SheafOfModules.{v} R}
theorem glueOn_over_eq_right (N P : M.Submodule) (U V : C)
    (h : ∀ (Z : C) (_a : Z ⟶ U) (_b : Z ⟶ V),
      N.toSubmodule.obj (op Z) = P.toSubmodule.obj (op Z)) :
    (glueOn N P U V).over V = P.over V