Documentation

Mathlib.AlgebraicGeometry.Cover.Over

Covers of schemes over a base #

In this file we define the typeclass Cover.Over. For a cover 𝒰 of an S-scheme X, the datum 𝒰.Over S contains S-scheme structures on the components of 𝒰 and asserts that the component maps are morphisms of S-schemes.

We provide instances of 𝒰.Over S for standard constructions on covers.

@[reducible, inline]

Bundle an S-scheme with P into an object of P.Over ⊤ S.

Equations
  • X.asOverProp S h = { toComma := X.asOver S, prop := h }
Instances For
    @[reducible, inline]
    abbrev AlgebraicGeometry.Scheme.Hom.asOverProp {P : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} {X Y : AlgebraicGeometry.Scheme} (f : X.Hom Y) (S : AlgebraicGeometry.Scheme) [X.Over S] [Y.Over S] [f.IsOver S] {hX : P (X S)} {hY : P (Y S)} :
    X.asOverProp S hX Y.asOverProp S hY

    Bundle an S-morphism of S-scheme with P into a morphism in P.Over ⊤ S.

    Equations
    • f.asOverProp S = { toCommaMorphism := f.asOver S, prop_hom_left := trivial, prop_hom_right := trivial }
    Instances For

      A P-cover of a scheme X over S is a cover, where the components are over S and the component maps commute with the structure morphisms.

      Instances
        Equations

        The pullback of a cover of S-schemes along a morphism of S-schemes. This is not definitionally equal to AlgebraicGeometry.Scheme.Cover.pullbackCover, as here we take the pullback in Over S, whose underlying scheme is only isomorphic but not equal to the pullback in Scheme.

        Equations
        • One or more equations did not get rendered due to their size.
        Instances For

          A variant of AlgebraicGeometry.Scheme.Cover.pullbackCoverOver with the arguments in the fiber products flipped.

          Equations
          • One or more equations did not get rendered due to their size.
          Instances For
            def AlgebraicGeometry.Scheme.Cover.pullbackCoverOverProp {P : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} (S : AlgebraicGeometry.Scheme) [P.IsStableUnderBaseChange] [AlgebraicGeometry.Scheme.IsJointlySurjectivePreserving P] {X W : AlgebraicGeometry.Scheme} (𝒰 : AlgebraicGeometry.Scheme.Cover P X) (f : W X) [W.Over S] [X.Over S] [AlgebraicGeometry.Scheme.Cover.Over S 𝒰] [AlgebraicGeometry.Scheme.Hom.IsOver f S] {Q : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} [Q.HasOfPostcompProperty Q] [Q.IsStableUnderBaseChange] [Q.IsStableUnderComposition] (hX : Q (X S)) (hW : Q (W S)) (hQ : ∀ (j : 𝒰.J), Q (𝒰.obj j S)) :

            The pullback of a cover of S-schemes with Q along a morphism of S-schemes. This is not definitionally equal to AlgebraicGeometry.Scheme.Cover.pullbackCover, as here we take the pullback in Q.Over ⊤ S, whose underlying scheme is only isomorphic but not equal to the pullback in Scheme.

            Equations
            • One or more equations did not get rendered due to their size.
            Instances For
              theorem AlgebraicGeometry.Scheme.Cover.pullbackCoverOverProp_map {P : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} (S : AlgebraicGeometry.Scheme) [P.IsStableUnderBaseChange] [AlgebraicGeometry.Scheme.IsJointlySurjectivePreserving P] {X W : AlgebraicGeometry.Scheme} (𝒰 : AlgebraicGeometry.Scheme.Cover P X) (f : W X) [W.Over S] [X.Over S] [AlgebraicGeometry.Scheme.Cover.Over S 𝒰] [AlgebraicGeometry.Scheme.Hom.IsOver f S] {Q : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} [Q.HasOfPostcompProperty Q] [Q.IsStableUnderBaseChange] [Q.IsStableUnderComposition] (hX : Q (X S)) (hW : Q (W S)) (hQ : ∀ (j : 𝒰.J), Q (𝒰.obj j S)) (x : 𝒰.J) :
              theorem AlgebraicGeometry.Scheme.Cover.pullbackCoverOverProp_J {P : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} (S : AlgebraicGeometry.Scheme) [P.IsStableUnderBaseChange] [AlgebraicGeometry.Scheme.IsJointlySurjectivePreserving P] {X W : AlgebraicGeometry.Scheme} (𝒰 : AlgebraicGeometry.Scheme.Cover P X) (f : W X) [W.Over S] [X.Over S] [AlgebraicGeometry.Scheme.Cover.Over S 𝒰] [AlgebraicGeometry.Scheme.Hom.IsOver f S] {Q : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} [Q.HasOfPostcompProperty Q] [Q.IsStableUnderBaseChange] [Q.IsStableUnderComposition] (hX : Q (X S)) (hW : Q (W S)) (hQ : ∀ (j : 𝒰.J), Q (𝒰.obj j S)) :
              theorem AlgebraicGeometry.Scheme.Cover.pullbackCoverOverProp_obj {P : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} (S : AlgebraicGeometry.Scheme) [P.IsStableUnderBaseChange] [AlgebraicGeometry.Scheme.IsJointlySurjectivePreserving P] {X W : AlgebraicGeometry.Scheme} (𝒰 : AlgebraicGeometry.Scheme.Cover P X) (f : W X) [W.Over S] [X.Over S] [AlgebraicGeometry.Scheme.Cover.Over S 𝒰] [AlgebraicGeometry.Scheme.Hom.IsOver f S] {Q : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} [Q.HasOfPostcompProperty Q] [Q.IsStableUnderBaseChange] [Q.IsStableUnderComposition] (hX : Q (X S)) (hW : Q (W S)) (hQ : ∀ (j : 𝒰.J), Q (𝒰.obj j S)) (x : 𝒰.J) :
              theorem AlgebraicGeometry.Scheme.Cover.pullbackCoverOverProp_f {P : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} (S : AlgebraicGeometry.Scheme) [P.IsStableUnderBaseChange] [AlgebraicGeometry.Scheme.IsJointlySurjectivePreserving P] {X W : AlgebraicGeometry.Scheme} (𝒰 : AlgebraicGeometry.Scheme.Cover P X) (f : W X) [W.Over S] [X.Over S] [AlgebraicGeometry.Scheme.Cover.Over S 𝒰] [AlgebraicGeometry.Scheme.Hom.IsOver f S] {Q : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} [Q.HasOfPostcompProperty Q] [Q.IsStableUnderBaseChange] [Q.IsStableUnderComposition] (hX : Q (X S)) (hW : Q (W S)) (hQ : ∀ (j : 𝒰.J), Q (𝒰.obj j S)) (x : W.toPresheafedSpace) :
              (AlgebraicGeometry.Scheme.Cover.pullbackCoverOverProp S 𝒰 f hX hW hQ).f x = 𝒰.f (f.base x)
              instance AlgebraicGeometry.Scheme.instOverObjPullbackCoverOverProp {P : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} (S : AlgebraicGeometry.Scheme) [P.IsStableUnderBaseChange] [AlgebraicGeometry.Scheme.IsJointlySurjectivePreserving P] {X W : AlgebraicGeometry.Scheme} (𝒰 : AlgebraicGeometry.Scheme.Cover P X) (f : W X) [W.Over S] [X.Over S] [AlgebraicGeometry.Scheme.Cover.Over S 𝒰] [AlgebraicGeometry.Scheme.Hom.IsOver f S] {Q : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} [Q.HasOfPostcompProperty Q] [Q.IsStableUnderBaseChange] [Q.IsStableUnderComposition] (hX : Q (X S)) (hW : Q (W S)) (hQ : ∀ (j : 𝒰.J), Q (𝒰.obj j S)) (j : 𝒰.J) :
              ((AlgebraicGeometry.Scheme.Cover.pullbackCoverOverProp S 𝒰 f hX hW hQ).obj j).Over S
              Equations
              • One or more equations did not get rendered due to their size.
              instance AlgebraicGeometry.Scheme.instOverPullbackCoverOverProp {P : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} (S : AlgebraicGeometry.Scheme) [P.IsStableUnderBaseChange] [AlgebraicGeometry.Scheme.IsJointlySurjectivePreserving P] {X W : AlgebraicGeometry.Scheme} (𝒰 : AlgebraicGeometry.Scheme.Cover P X) (f : W X) [W.Over S] [X.Over S] [AlgebraicGeometry.Scheme.Cover.Over S 𝒰] [AlgebraicGeometry.Scheme.Hom.IsOver f S] {Q : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} [Q.HasOfPostcompProperty Q] [Q.IsStableUnderBaseChange] [Q.IsStableUnderComposition] (hX : Q (X S)) (hW : Q (W S)) (hQ : ∀ (j : 𝒰.J), Q (𝒰.obj j S)) :
              Equations
              • S.instOverPullbackCoverOverProp 𝒰 f hX hW hQ = { over := inferInstance, isOver_map := }
              def AlgebraicGeometry.Scheme.Cover.pullbackCoverOverProp' {P : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} (S : AlgebraicGeometry.Scheme) [P.IsStableUnderBaseChange] [AlgebraicGeometry.Scheme.IsJointlySurjectivePreserving P] {X W : AlgebraicGeometry.Scheme} (𝒰 : AlgebraicGeometry.Scheme.Cover P X) (f : W X) [W.Over S] [X.Over S] [AlgebraicGeometry.Scheme.Cover.Over S 𝒰] [AlgebraicGeometry.Scheme.Hom.IsOver f S] {Q : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} [Q.HasOfPostcompProperty Q] [Q.IsStableUnderBaseChange] [Q.IsStableUnderComposition] (hX : Q (X S)) (hW : Q (W S)) (hQ : ∀ (j : 𝒰.J), Q (𝒰.obj j S)) :

              A variant of AlgebraicGeometry.Scheme.Cover.pullbackCoverOverProp with the arguments in the fiber products flipped.

              Equations
              • One or more equations did not get rendered due to their size.
              Instances For
                theorem AlgebraicGeometry.Scheme.Cover.pullbackCoverOverProp'_obj {P : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} (S : AlgebraicGeometry.Scheme) [P.IsStableUnderBaseChange] [AlgebraicGeometry.Scheme.IsJointlySurjectivePreserving P] {X W : AlgebraicGeometry.Scheme} (𝒰 : AlgebraicGeometry.Scheme.Cover P X) (f : W X) [W.Over S] [X.Over S] [AlgebraicGeometry.Scheme.Cover.Over S 𝒰] [AlgebraicGeometry.Scheme.Hom.IsOver f S] {Q : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} [Q.HasOfPostcompProperty Q] [Q.IsStableUnderBaseChange] [Q.IsStableUnderComposition] (hX : Q (X S)) (hW : Q (W S)) (hQ : ∀ (j : 𝒰.J), Q (𝒰.obj j S)) (x : 𝒰.J) :
                theorem AlgebraicGeometry.Scheme.Cover.pullbackCoverOverProp'_J {P : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} (S : AlgebraicGeometry.Scheme) [P.IsStableUnderBaseChange] [AlgebraicGeometry.Scheme.IsJointlySurjectivePreserving P] {X W : AlgebraicGeometry.Scheme} (𝒰 : AlgebraicGeometry.Scheme.Cover P X) (f : W X) [W.Over S] [X.Over S] [AlgebraicGeometry.Scheme.Cover.Over S 𝒰] [AlgebraicGeometry.Scheme.Hom.IsOver f S] {Q : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} [Q.HasOfPostcompProperty Q] [Q.IsStableUnderBaseChange] [Q.IsStableUnderComposition] (hX : Q (X S)) (hW : Q (W S)) (hQ : ∀ (j : 𝒰.J), Q (𝒰.obj j S)) :
                theorem AlgebraicGeometry.Scheme.Cover.pullbackCoverOverProp'_f {P : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} (S : AlgebraicGeometry.Scheme) [P.IsStableUnderBaseChange] [AlgebraicGeometry.Scheme.IsJointlySurjectivePreserving P] {X W : AlgebraicGeometry.Scheme} (𝒰 : AlgebraicGeometry.Scheme.Cover P X) (f : W X) [W.Over S] [X.Over S] [AlgebraicGeometry.Scheme.Cover.Over S 𝒰] [AlgebraicGeometry.Scheme.Hom.IsOver f S] {Q : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} [Q.HasOfPostcompProperty Q] [Q.IsStableUnderBaseChange] [Q.IsStableUnderComposition] (hX : Q (X S)) (hW : Q (W S)) (hQ : ∀ (j : 𝒰.J), Q (𝒰.obj j S)) (x : W.toPresheafedSpace) :
                (AlgebraicGeometry.Scheme.Cover.pullbackCoverOverProp' S 𝒰 f hX hW hQ).f x = 𝒰.f (f.base x)
                theorem AlgebraicGeometry.Scheme.Cover.pullbackCoverOverProp'_map {P : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} (S : AlgebraicGeometry.Scheme) [P.IsStableUnderBaseChange] [AlgebraicGeometry.Scheme.IsJointlySurjectivePreserving P] {X W : AlgebraicGeometry.Scheme} (𝒰 : AlgebraicGeometry.Scheme.Cover P X) (f : W X) [W.Over S] [X.Over S] [AlgebraicGeometry.Scheme.Cover.Over S 𝒰] [AlgebraicGeometry.Scheme.Hom.IsOver f S] {Q : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} [Q.HasOfPostcompProperty Q] [Q.IsStableUnderBaseChange] [Q.IsStableUnderComposition] (hX : Q (X S)) (hW : Q (W S)) (hQ : ∀ (j : 𝒰.J), Q (𝒰.obj j S)) (x : 𝒰.J) :
                instance AlgebraicGeometry.Scheme.instOverObjPullbackCoverOverProp' {P : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} (S : AlgebraicGeometry.Scheme) [P.IsStableUnderBaseChange] [AlgebraicGeometry.Scheme.IsJointlySurjectivePreserving P] {X W : AlgebraicGeometry.Scheme} (𝒰 : AlgebraicGeometry.Scheme.Cover P X) (f : W X) [W.Over S] [X.Over S] [AlgebraicGeometry.Scheme.Cover.Over S 𝒰] [AlgebraicGeometry.Scheme.Hom.IsOver f S] {Q : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} [Q.HasOfPostcompProperty Q] [Q.IsStableUnderBaseChange] [Q.IsStableUnderComposition] (hX : Q (X S)) (hW : Q (W S)) (hQ : ∀ (j : 𝒰.J), Q (𝒰.obj j S)) (j : 𝒰.J) :
                Equations
                • One or more equations did not get rendered due to their size.
                instance AlgebraicGeometry.Scheme.instOverPullbackCoverOverProp' {P : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} (S : AlgebraicGeometry.Scheme) [P.IsStableUnderBaseChange] [AlgebraicGeometry.Scheme.IsJointlySurjectivePreserving P] {X W : AlgebraicGeometry.Scheme} (𝒰 : AlgebraicGeometry.Scheme.Cover P X) (f : W X) [W.Over S] [X.Over S] [AlgebraicGeometry.Scheme.Cover.Over S 𝒰] [AlgebraicGeometry.Scheme.Hom.IsOver f S] {Q : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} [Q.HasOfPostcompProperty Q] [Q.IsStableUnderBaseChange] [Q.IsStableUnderComposition] (hX : Q (X S)) (hW : Q (W S)) (hQ : ∀ (j : 𝒰.J), Q (𝒰.obj j S)) :
                Equations
                • S.instOverPullbackCoverOverProp' 𝒰 f hX hW hQ = { over := inferInstance, isOver_map := }
                instance AlgebraicGeometry.Scheme.instOverObjBind {P : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} (S : AlgebraicGeometry.Scheme) [P.IsStableUnderComposition] {X : AlgebraicGeometry.Scheme} (𝒰 : AlgebraicGeometry.Scheme.Cover P X) (𝒱 : (x : 𝒰.J) → AlgebraicGeometry.Scheme.Cover P (𝒰.obj x)) [X.Over S] [AlgebraicGeometry.Scheme.Cover.Over S 𝒰] [(x : 𝒰.J) → AlgebraicGeometry.Scheme.Cover.Over S (𝒱 x)] (j : (𝒰.bind 𝒱).J) :
                ((𝒰.bind 𝒱).obj j).Over S
                Equations
                • S.instOverObjBind 𝒰 𝒱 j = inferInstanceAs (((𝒱 j.fst).obj j.snd).Over S)
                Equations
                • S.instOverBind 𝒰 𝒱 = { over := fun (x : (𝒰.bind 𝒱).J) => match x with | i, j => inferInstanceAs (((𝒱 i).obj j).Over S), isOver_map := }