ProCGroups.FoxDifferential.Completed.FreeProC.Uniqueness.Derivative
The principal declarations in this module are:
freeProCZCCompletedFoxDerivativeVector_unique_of_semidirectAny continuous semidirect lift with the prescribed generator components has the canonical free pro-\(C\) completed Fox derivative vector as its left component. -freeProCZCCompletedFoxDerivativeVector_unique_of_continuousCrossedDifferentialContinuous completed crossed differentials on a free pro-\(C\) source are uniquely determined by their standard generator values, provided their semidirect graph is continuous. -freeProCZCCompletedCrossedDifferential_extExtensionality for continuous completed crossed differentials on a free pro-\(C\) source. The continuity hypotheses are put on the associated semidirect homomorphisms, which is the form used by the completed Fox construction before the target topology is fully structural. -freeProCZCCompletedFoxRightHom_eq_of_continuousCrossedDifferentialThe coefficient homomorphism of a continuous completed crossed differential agrees with the right component of the canonical free pro-\(C\) semidirect lift.
theorem freeProCZCCompletedFoxDerivativeVector_unique_of_semidirect
{ι : X → F} (hι : IsFreeProCGroup (C := C) ι)
(htarget : ProCGroups.ProC.HasOpenNormalBasisInClass C (ZCCompletedFoxSemidirect C X H))
(φ : X → H)
(hφ : Continuous (freeProCZCCompletedFoxSemidirectGenerator (C := C) φ))
(f : F →* ZCCompletedFoxSemidirect C X H)
(hf : Continuous f)
(hleft :
∀ x : X, (f (ι x)).left =
Pi.single x (1 : ZCCompletedGroupAlgebra C H))
(hright : ∀ x : X, (f (ι x)).right = φ x) :
(fun g : F => (f g).left) =
freeProCZCCompletedFoxDerivativeVector
(C := C) hι htarget φ hφAny continuous semidirect lift with the prescribed generator components has the canonical free pro-\(C\) completed Fox derivative vector as its left component.
Show Lean proof
by
have hgenerator :
∀ x : X, f (ι x) = freeProCZCCompletedFoxSemidirectGenerator (C := C) φ x := by
intro x
apply ZCCompletedFoxSemidirect.ext
· exact hleft x
· exact hright x
have hf_eq := hι.lift_unique htarget
(freeProCZCCompletedFoxSemidirectGenerator (C := C) φ) hφ hf hgenerator
funext g
rw [hf_eq]
rfl
theorem freeProCZCCompletedFoxDerivativeVector_unique_of_continuousCrossedDifferential
{ι : X → F} (hι : IsFreeProCGroup (C := C) ι)
(htarget : ProCGroups.ProC.HasOpenNormalBasisInClass C (ZCCompletedFoxSemidirect C X H))
(ψ : F →* H)
(delta : ScalarCrossedHom (zcCompletedGroupAlgebraScalar C ψ)
(ZCFreeFoxCoordinates C (X := X) (H := H)))
(hcontinuous :
Continuous (freeProCZCCompletedFoxSemidirectHomOfCrossedDifferential
(X := X) ψ delta))
(hbasis :
∀ x : X, delta (ι x) = Pi.single x (1 : ZCCompletedGroupAlgebra C H)) :
(fun g : F => delta g) =
fun g : F =>
freeProCZCCompletedFoxDerivativeVector
(C := C) hι htarget (fun x : X => ψ (ι x))
(continuous_freeProCZCCompletedFoxSemidirectGenerator_of_crossedDifferential
(C := C) hι ψ delta hcontinuous hbasis) gContinuous completed crossed differentials on a free pro-\(C\) source are uniquely determined by their standard generator values, provided their semidirect graph is continuous.
Show Lean proof
by
have hleft :
∀ x : X,
(freeProCZCCompletedFoxSemidirectHomOfCrossedDifferential
(X := X) ψ delta (ι x)).left =
Pi.single x (1 : ZCCompletedGroupAlgebra C H) := by
intro x
exact hbasis x
have hright :
∀ x : X,
(freeProCZCCompletedFoxSemidirectHomOfCrossedDifferential
(X := X) ψ delta (ι x)).right = ψ (ι x) := by
intro x
rfl
have hunique := freeProCZCCompletedFoxDerivativeVector_unique_of_semidirect
(C := C) hι htarget (fun x : X => ψ (ι x))
(continuous_freeProCZCCompletedFoxSemidirectGenerator_of_crossedDifferential
(C := C) hι ψ delta hcontinuous hbasis)
(freeProCZCCompletedFoxSemidirectHomOfCrossedDifferential
(X := X) ψ delta)
hcontinuous hleft hright
simpa using hunique
omit [DecidableEq X] in
theorem freeProCZCCompletedCrossedDifferential_ext
{ι : X → F} (hι : IsFreeProCGroup (C := C) ι)
(htarget : ProCGroups.ProC.HasOpenNormalBasisInClass C (ZCCompletedFoxSemidirect C X H))
(ψ : F →* H)
(delta epsilon :
ScalarCrossedHom (zcCompletedGroupAlgebraScalar C ψ)
(ZCFreeFoxCoordinates C (X := X) (H := H)))
(hdelta_continuous :
Continuous (freeProCZCCompletedFoxSemidirectHomOfCrossedDifferential
(X := X) ψ delta))
(hepsilon_continuous :
Continuous (freeProCZCCompletedFoxSemidirectHomOfCrossedDifferential
(X := X) ψ epsilon))
(hbasis : ∀ x : X, delta (ι x) = epsilon (ι x)) :
delta = epsilonExtensionality for continuous completed crossed differentials on a free pro-\(C\) source. The continuity hypotheses are put on the associated semidirect homomorphisms, which is the form used by the completed Fox construction before the target topology is fully structural.
Show Lean proof
by
let f : F →* ZCCompletedFoxSemidirect C X H :=
freeProCZCCompletedFoxSemidirectHomOfCrossedDifferential
(X := X) ψ delta
let g : F →* ZCCompletedFoxSemidirect C X H :=
freeProCZCCompletedFoxSemidirectHomOfCrossedDifferential
(X := X) ψ epsilon
have hfg : ∀ x : X, f (ι x) = g (ι x) := by
intro x
apply ZCCompletedFoxSemidirect.ext
· exact hbasis x
· rfl
have hsemidirect : f = g := hι.hom_ext htarget hdelta_continuous hepsilon_continuous hfg
apply CrossedHom.ext
intro a
exact congrArg
(fun q : F →* ZCCompletedFoxSemidirect C X H => (q a).left)
hsemidirect
theorem freeProCZCCompletedFoxRightHom_eq_of_continuousCrossedDifferential
{ι : X → F} (hι : IsFreeProCGroup (C := C) ι)
(htarget : ProCGroups.ProC.HasOpenNormalBasisInClass C (ZCCompletedFoxSemidirect C X H))
(ψ : F →* H)
(delta : ScalarCrossedHom (zcCompletedGroupAlgebraScalar C ψ)
(ZCFreeFoxCoordinates C (X := X) (H := H)))
(hcontinuous :
Continuous (freeProCZCCompletedFoxSemidirectHomOfCrossedDifferential
(X := X) ψ delta))
(hbasis :
∀ x : X, delta (ι x) = Pi.single x (1 : ZCCompletedGroupAlgebra C H)) :
ψ =
freeProCZCCompletedFoxRightHom
(C := C) hι htarget (fun x : X => ψ (ι x))
(continuous_freeProCZCCompletedFoxSemidirectGenerator_of_crossedDifferential
(C := C) hι ψ delta hcontinuous hbasis)The coefficient homomorphism of a continuous completed crossed differential agrees with the right component of the canonical free pro-\(C\) semidirect lift.
Show Lean proof
by
apply MonoidHom.ext
intro g
have hgenerator :
∀ x : X,
freeProCZCCompletedFoxSemidirectHomOfCrossedDifferential
(X := X) ψ delta (ι x) =
freeProCZCCompletedFoxSemidirectGenerator (C := C) (fun x : X => ψ (ι x)) x := by
intro x
apply ZCCompletedFoxSemidirect.ext
· exact hbasis x
· rfl
have hsemidirect := hι.lift_unique htarget
(freeProCZCCompletedFoxSemidirectGenerator (C := C) (fun x : X => ψ (ι x)))
(continuous_freeProCZCCompletedFoxSemidirectGenerator_of_crossedDifferential
(C := C) hι ψ delta hcontinuous hbasis)
(f := freeProCZCCompletedFoxSemidirectHomOfCrossedDifferential
(X := X) ψ delta)
hcontinuous hgenerator
change ψ g =
((hι.lift htarget
(freeProCZCCompletedFoxSemidirectGenerator (C := C) (fun x : X => ψ (ι x)))
(continuous_freeProCZCCompletedFoxSemidirectGenerator_of_crossedDifferential
(C := C) hι ψ delta hcontinuous hbasis)) g).right
exact congrArg
(fun f : F →* ZCCompletedFoxSemidirect C X H => (f g).right) hsemidirect