Module

Basic.lean

Nyll.ProCGroups.FoxDifferential.Completed.FiniteStage.PrimePower.System.Basic
18 declarations indexed from sourceView source ↗

Fox differential: finite stage — prime power — system — basic

The principal declarations in this module are:

  • foxAlgebraicStagePrimePowerSourceGroupAlgebra

Source group algebra at the \(\ell^a\) finite Fox stage.

  • foxAlgebraicStagePrimePowerTargetGroupAlgebra

Target group algebra at the \(\ell^a\) finite Fox stage.

  • foxAlgebraicStagePrimePowerFreeGroupAlgebraTransition_of

Coefficient reduction sends a group-like free-group element to the same group-like element at the lower prime-power stage.

  • foxAlgebraicStagePrimePowerSourceProjection_of

Evaluation of the source projection on a group-like free-group algebra element.

Declarations

FoxDifferential.foxAlgebraicStagePrimePowerSourceGroupAlgebra

Source group algebra at the \(\ell^a\) finite Fox stage.

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open ProCGroups.InverseSystems
open ProCGroups.ProC
universe u v
variable (ℓ : ℕ) [Fact (0 < ℓ)]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
variable {X : Type u} [DecidableEq X]
variable (N : Subgroup (FreeGroup X)) [N.Normal] (n : ℕ)
omit [Fact (0 < ℓ)] in
abbrev foxAlgebraicStagePrimePowerSourceGroupAlgebra
    (N : Subgroup (FreeGroup X)) (a : ℕ) : Type u
FoxDifferential.foxAlgebraicStagePrimePowerTargetGroupAlgebra

Target group algebra at the \(\ell^a\) finite Fox stage.

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open ProCGroups.InverseSystems
open ProCGroups.ProC
universe u v
variable (ℓ : ℕ) [Fact (0 < ℓ)]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
variable {X : Type u} [DecidableEq X]
variable (N : Subgroup (FreeGroup X)) [N.Normal] (n : ℕ)
omit [Fact (0 < ℓ)] in
abbrev foxAlgebraicStagePrimePowerTargetGroupAlgebra
    (N : Subgroup (FreeGroup X)) (a : ℕ) : Type u
FoxDifferential.foxAlgebraicStagePrimePowerFreeGroupAlgebra

The free-group algebra with coefficients modulo \(\ell^a\).

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open ProCGroups.InverseSystems
open ProCGroups.ProC
universe u v
variable (ℓ : ℕ) [Fact (0 < ℓ)]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
variable {X : Type u} [DecidableEq X]
variable (N : Subgroup (FreeGroup X)) [N.Normal] (n : ℕ)
omit [Fact (0 < ℓ)] in
abbrev foxAlgebraicStagePrimePowerFreeGroupAlgebra (a : ℕ) : Type u
FoxDifferential.foxAlgebraicStagePrimePowerFreeGroupAlgebraTransition

Coefficient reduction on free-group algebras between prime-power stages.

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open ProCGroups.InverseSystems
open ProCGroups.ProC
universe u v
variable (ℓ : ℕ) [Fact (0 < ℓ)]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
variable {X : Type u} [DecidableEq X]
variable (N : Subgroup (FreeGroup X)) [N.Normal] (n : ℕ)
omit [Fact (0 < ℓ)] in
def foxAlgebraicStagePrimePowerFreeGroupAlgebraTransition
    {a b : ℕ} (hab : a ≤ b) :
    foxAlgebraicStagePrimePowerFreeGroupAlgebra (ℓ := ℓ) (X := X) b →+*
      foxAlgebraicStagePrimePowerFreeGroupAlgebra (ℓ := ℓ) (X := X) a
FoxDifferential.foxAlgebraicStagePrimePowerFreeGroupAlgebraTransition_of

Coefficient reduction sends a group-like free-group element to the same group-like element at the lower prime-power stage.

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open ProCGroups.InverseSystems
open ProCGroups.ProC
universe u v
variable (ℓ : ℕ) [Fact (0 < ℓ)]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
variable {X : Type u} [DecidableEq X]
variable (N : Subgroup (FreeGroup X)) [N.Normal] (n : ℕ)
omit [DecidableEq X] [Fact (0 < ℓ)] in
theorem foxAlgebraicStagePrimePowerFreeGroupAlgebraTransition_of
    {a b : ℕ} (hab : a ≤ b) (w : FreeGroup X) :
    foxAlgebraicStagePrimePowerFreeGroupAlgebraTransition (ℓ := ℓ) (X := X) hab
        (MonoidAlgebra.of (ModNCompletedCoeff (ℓ ^ b)) (FreeGroup X) w) =
      MonoidAlgebra.of (ModNCompletedCoeff (ℓ ^ a)) (FreeGroup X) w
FoxDifferential.foxAlgebraicStagePrimePowerSourceProjection

The projection from the free-group algebra to the finite Fox source quotient at a prime-power stage.

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open ProCGroups.InverseSystems
open ProCGroups.ProC
universe u v
variable (ℓ : ℕ) [Fact (0 < ℓ)]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
variable {X : Type u} [DecidableEq X]
variable (N : Subgroup (FreeGroup X)) [N.Normal] (n : ℕ)
omit [Fact (0 < ℓ)] in
def foxAlgebraicStagePrimePowerSourceProjection
    (N : Subgroup (FreeGroup X)) (a : ℕ) :
    foxAlgebraicStagePrimePowerFreeGroupAlgebra (ℓ := ℓ) (X := X) a →+*
      foxAlgebraicStagePrimePowerSourceGroupAlgebra (ℓ := ℓ) (X := X) N a
FoxDifferential.foxAlgebraicStagePrimePowerSourceProjection_of

Evaluation of the source projection on a group-like free-group algebra element.

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open ProCGroups.InverseSystems
open ProCGroups.ProC
universe u v
variable (ℓ : ℕ) [Fact (0 < ℓ)]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
variable {X : Type u} [DecidableEq X]
variable (N : Subgroup (FreeGroup X)) [N.Normal] (n : ℕ)
omit [DecidableEq X] [Fact (0 < ℓ)] in
theorem foxAlgebraicStagePrimePowerSourceProjection_of
    (N : Subgroup (FreeGroup X)) (a : ℕ) (w : FreeGroup X) :
    foxAlgebraicStagePrimePowerSourceProjection (ℓ := ℓ) (X := X) N a
        (MonoidAlgebra.of (ModNCompletedCoeff (ℓ ^ a)) (FreeGroup X) w) =
      MonoidAlgebra.of (ModNCompletedCoeff (ℓ ^ a))
        (FreeGroup X ⧸
          foxCommutatorPowerSubgroup (F := FreeGroup X) N (ℓ ^ a))
        (QuotientGroup.mk'
          (foxCommutatorPowerSubgroup (F := FreeGroup X) N (ℓ ^ a)) w)
FoxDifferential.foxAlgebraicStagePrimePowerSourceTransition

Transition map for the finite Fox source quotient group algebras along prime-power stages.

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open ProCGroups.InverseSystems
open ProCGroups.ProC
universe u v
variable (ℓ : ℕ) [Fact (0 < ℓ)]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
variable {X : Type u} [DecidableEq X]
variable (N : Subgroup (FreeGroup X)) [N.Normal] (n : ℕ)
omit [Fact (0 < ℓ)] in
def foxAlgebraicStagePrimePowerSourceTransition
    (N : Subgroup (FreeGroup X)) {a b : ℕ} (hab : a ≤ b) :
    foxAlgebraicStagePrimePowerSourceGroupAlgebra (ℓ := ℓ) (X := X) N b →+*
      foxAlgebraicStagePrimePowerSourceGroupAlgebra (ℓ := ℓ) (X := X) N a
FoxDifferential.foxAlgebraicStagePrimePowerSourceTransition_of

Evaluation of a source transition map on a group-like quotient element.

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open ProCGroups.InverseSystems
open ProCGroups.ProC
universe u v
variable (ℓ : ℕ) [Fact (0 < ℓ)]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
variable {X : Type u} [DecidableEq X]
variable (N : Subgroup (FreeGroup X)) [N.Normal] (n : ℕ)
omit [DecidableEq X] [Fact (0 < ℓ)] in
theorem foxAlgebraicStagePrimePowerSourceTransition_of
    (N : Subgroup (FreeGroup X)) {a b : ℕ} (hab : a ≤ b) (w : FreeGroup X) :
    foxAlgebraicStagePrimePowerSourceTransition (ℓ := ℓ) (X := X) N hab
        (MonoidAlgebra.of (ModNCompletedCoeff (ℓ ^ b))
          (FreeGroup X ⧸
            foxCommutatorPowerSubgroup (F := FreeGroup X) N (ℓ ^ b))
          (QuotientGroup.mk'
            (foxCommutatorPowerSubgroup (F := FreeGroup X) N (ℓ ^ b)) w)) =
      MonoidAlgebra.of (ModNCompletedCoeff (ℓ ^ a))
        (FreeGroup X ⧸
          foxCommutatorPowerSubgroup (F := FreeGroup X) N (ℓ ^ a))
        (QuotientGroup.mk'
          (foxCommutatorPowerSubgroup (F := FreeGroup X) N (ℓ ^ a)) w)
FoxDifferential.foxAlgebraicStagePrimePowerSourceTransition_id

The source transition map from a stage to itself is the identity.

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open ProCGroups.InverseSystems
open ProCGroups.ProC
universe u v
variable (ℓ : ℕ) [Fact (0 < ℓ)]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
variable {X : Type u} [DecidableEq X]
variable (N : Subgroup (FreeGroup X)) [N.Normal] (n : ℕ)
omit [DecidableEq X] [Fact (0 < ℓ)] in
theorem foxAlgebraicStagePrimePowerSourceTransition_id
    (N : Subgroup (FreeGroup X)) (a : ℕ) :
    foxAlgebraicStagePrimePowerSourceTransition (ℓ := ℓ) (X := X) N
        (le_rfl : a ≤ a) =
      RingHom.id _
FoxDifferential.foxAlgebraicStagePrimePowerSourceTransition_comp

Source transition maps compose along the order on prime-power stages.

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open ProCGroups.InverseSystems
open ProCGroups.ProC
universe u v
variable (ℓ : ℕ) [Fact (0 < ℓ)]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
variable {X : Type u} [DecidableEq X]
variable (N : Subgroup (FreeGroup X)) [N.Normal] (n : ℕ)
omit [DecidableEq X] [Fact (0 < ℓ)] in
theorem foxAlgebraicStagePrimePowerSourceTransition_comp
    (N : Subgroup (FreeGroup X)) {a b c : ℕ} (hab : a ≤ b) (hbc : b ≤ c) :
    (foxAlgebraicStagePrimePowerSourceTransition (ℓ := ℓ) (X := X) N hab).comp
        (foxAlgebraicStagePrimePowerSourceTransition (ℓ := ℓ) (X := X) N hbc) =
      foxAlgebraicStagePrimePowerSourceTransition (ℓ := ℓ) (X := X) N (hab.trans hbc)
FoxDifferential.foxAlgebraicStagePrimePowerSourceProjection_transition

Source projection commutes with coefficient reduction and the source transition map.

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open ProCGroups.InverseSystems
open ProCGroups.ProC
universe u v
variable (ℓ : ℕ) [Fact (0 < ℓ)]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
variable {X : Type u} [DecidableEq X]
variable (N : Subgroup (FreeGroup X)) [N.Normal] (n : ℕ)
omit [DecidableEq X] [Fact (0 < ℓ)] in
theorem foxAlgebraicStagePrimePowerSourceProjection_transition
    (N : Subgroup (FreeGroup X)) {a b : ℕ} (hab : a ≤ b) :
    (foxAlgebraicStagePrimePowerSourceTransition (ℓ := ℓ) (X := X) N hab).comp
        (foxAlgebraicStagePrimePowerSourceProjection (ℓ := ℓ) (X := X) N b) =
      (foxAlgebraicStagePrimePowerSourceProjection (ℓ := ℓ) (X := X) N a).comp
        (foxAlgebraicStagePrimePowerFreeGroupAlgebraTransition (ℓ := ℓ) (X := X) hab)
FoxDifferential.foxAlgebraicStagePrimePowerTargetTransition

Transition map for the finite Fox target group algebras along prime-power stages.

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open ProCGroups.InverseSystems
open ProCGroups.ProC
universe u v
variable (ℓ : ℕ) [Fact (0 < ℓ)]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
variable {X : Type u} [DecidableEq X]
variable (N : Subgroup (FreeGroup X)) [N.Normal] (n : ℕ)
omit [Fact (0 < ℓ)] in
def foxAlgebraicStagePrimePowerTargetTransition
    (N : Subgroup (FreeGroup X)) [N.Normal] {a b : ℕ} (hab : a ≤ b) :
    foxAlgebraicStagePrimePowerTargetGroupAlgebra (ℓ := ℓ) (X := X) N b →+*
      foxAlgebraicStagePrimePowerTargetGroupAlgebra (ℓ := ℓ) (X := X) N a
FoxDifferential.foxAlgebraicStagePrimePowerTargetTransition_of

Evaluation of a target transition map on a group-like target quotient element.

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open ProCGroups.InverseSystems
open ProCGroups.ProC
universe u v
variable (ℓ : ℕ) [Fact (0 < ℓ)]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
variable {X : Type u} [DecidableEq X]
variable (N : Subgroup (FreeGroup X)) [N.Normal] (n : ℕ)
omit [DecidableEq X] [Fact (0 < ℓ)] in
theorem foxAlgebraicStagePrimePowerTargetTransition_of
    (N : Subgroup (FreeGroup X)) [N.Normal] {a b : ℕ} (hab : a ≤ b) (w : FreeGroup X) :
    foxAlgebraicStagePrimePowerTargetTransition (ℓ := ℓ) (X := X) N hab
        (MonoidAlgebra.of (ModNCompletedCoeff (ℓ ^ b))
          (foxAlgebraicStageTargetQuotient (X := X) N)
          (QuotientGroup.mk' N w)) =
      MonoidAlgebra.of (ModNCompletedCoeff (ℓ ^ a))
        (foxAlgebraicStageTargetQuotient (X := X) N)
        (QuotientGroup.mk' N w)
FoxDifferential.foxAlgebraicStagePrimePowerTargetTransition_id

The target transition map from a stage to itself is the identity.

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open ProCGroups.InverseSystems
open ProCGroups.ProC
universe u v
variable (ℓ : ℕ) [Fact (0 < ℓ)]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
variable {X : Type u} [DecidableEq X]
variable (N : Subgroup (FreeGroup X)) [N.Normal] (n : ℕ)
omit [DecidableEq X] [Fact (0 < ℓ)] in
theorem foxAlgebraicStagePrimePowerTargetTransition_id
    (N : Subgroup (FreeGroup X)) [N.Normal] (a : ℕ) :
    foxAlgebraicStagePrimePowerTargetTransition (ℓ := ℓ) (X := X) N
        (le_rfl : a ≤ a) =
      RingHom.id _
FoxDifferential.foxAlgebraicStagePrimePowerTargetTransition_comp

Target transition maps compose along the order on prime-power stages.

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open ProCGroups.InverseSystems
open ProCGroups.ProC
universe u v
variable (ℓ : ℕ) [Fact (0 < ℓ)]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
variable {X : Type u} [DecidableEq X]
variable (N : Subgroup (FreeGroup X)) [N.Normal] (n : ℕ)
omit [DecidableEq X] [Fact (0 < ℓ)] in
theorem foxAlgebraicStagePrimePowerTargetTransition_comp
    (N : Subgroup (FreeGroup X)) [N.Normal] {a b c : ℕ} (hab : a ≤ b) (hbc : b ≤ c) :
    (foxAlgebraicStagePrimePowerTargetTransition (ℓ := ℓ) (X := X) N hab).comp
        (foxAlgebraicStagePrimePowerTargetTransition (ℓ := ℓ) (X := X) N hbc) =
      foxAlgebraicStagePrimePowerTargetTransition (ℓ := ℓ) (X := X) N (hab.trans hbc)
FoxDifferential.foxAlgebraicStagePrimePowerSourceSystem

The inverse system of finite Fox source quotient group algebras over prime-power stages.

Source context 10 commands

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

namespace FoxDifferential
noncomputable section
open ProCGroups.InverseSystems
open ProCGroups.ProC
universe u v
variable (ℓ : ℕ) [Fact (0 < ℓ)]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
variable {X : Type u} [DecidableEq X]
variable (N : Subgroup (FreeGroup X)) [N.Normal] (n : ℕ)
def foxAlgebraicStagePrimePowerSourceSystem
    (N : Subgroup (FreeGroup X)) :
    InverseSystem (I := ℕ) where
  X := foxAlgebraicStagePrimePowerSourceGroupAlgebra (ℓ := ℓ) (X := X) N
  topologicalSpace := fun _ => ⊥
  map := fun {a b} hab => foxAlgebraicStagePrimePowerSourceTransition (ℓ := ℓ) (X := X) N hab
  continuous_map := by
    intro a b hab
    let : TopologicalSpace
        (foxAlgebraicStagePrimePowerSourceGroupAlgebra (ℓ := ℓ) (X := X) N a) := ⊥
    let : TopologicalSpace
        (foxAlgebraicStagePrimePowerSourceGroupAlgebra (ℓ := ℓ) (X := X) N b) := ⊥
    let : DiscreteTopology
        (foxAlgebraicStagePrimePowerSourceGroupAlgebra (ℓ := ℓ) (X := X) N b) := ⟨rfl⟩
    exact continuous_of_discreteTopology
  map_id := by
    intro a
    funext x
    exact congrFun
      (congrArg DFunLike.coe
        (foxAlgebraicStagePrimePowerSourceTransition_id (ℓ := ℓ) (X := X) N a)) x
  map_comp := by
    intro a b c hab hbc
    funext x
    exact congrFun
      (congrArg DFunLike.coe
        (foxAlgebraicStagePrimePowerSourceTransition_comp
          (ℓ := ℓ) (X := X) N hab hbc)) x
FoxDifferential.foxAlgebraicStagePrimePowerTargetSystem

The inverse system of finite Fox target group algebras over prime-power stages.

Source context 10 commands

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

namespace FoxDifferential
noncomputable section
open ProCGroups.InverseSystems
open ProCGroups.ProC
universe u v
variable (ℓ : ℕ) [Fact (0 < ℓ)]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
variable {X : Type u} [DecidableEq X]
variable (N : Subgroup (FreeGroup X)) [N.Normal] (n : ℕ)
def foxAlgebraicStagePrimePowerTargetSystem
    (N : Subgroup (FreeGroup X)) [N.Normal] :
    InverseSystem (I := ℕ) where
  X := foxAlgebraicStagePrimePowerTargetGroupAlgebra (ℓ := ℓ) (X := X) N
  topologicalSpace := fun _ => ⊥
  map := fun {a b} hab => foxAlgebraicStagePrimePowerTargetTransition (ℓ := ℓ) (X := X) N hab
  continuous_map := by
    intro a b hab
    let : TopologicalSpace
        (foxAlgebraicStagePrimePowerTargetGroupAlgebra (ℓ := ℓ) (X := X) N a) := ⊥
    let : TopologicalSpace
        (foxAlgebraicStagePrimePowerTargetGroupAlgebra (ℓ := ℓ) (X := X) N b) := ⊥
    let : DiscreteTopology
        (foxAlgebraicStagePrimePowerTargetGroupAlgebra (ℓ := ℓ) (X := X) N b) := ⟨rfl⟩
    exact continuous_of_discreteTopology
  map_id := by
    intro a
    funext x
    exact congrFun
      (congrArg DFunLike.coe
        (foxAlgebraicStagePrimePowerTargetTransition_id (ℓ := ℓ) (X := X) N a)) x
  map_comp := by
    intro a b c hab hbc
    funext x
    exact congrFun
      (congrArg DFunLike.coe
      (foxAlgebraicStagePrimePowerTargetTransition_comp
          (ℓ := ℓ) (X := X) N hab hbc)) x