ProCGroups.FoxDifferential.Completed.Residue.FreeGroup.Fundamental
The principal declarations in this module are:
residueFreeGroupFoxBoundary_derivativeVectorBoundary-map form of the residue Fox fundamental formula. -residueFreeGroupFoxBoundary_of_crossedHomAny residue crossed homomorphism with the standard basis values satisfies the residue Fox boundary formula. -residueFreeGroupFoxDerivative_fundamental_formula_of_crossedHomThe residue Fox-Euler sum computed from a crossed homomorphism with standard basis values is \([\psi(w)]-1\). -residueFreeGroupFoxDerivative_euler_formula_of_crossedHomThe explicit \([\psi(w)]-1\) form of the residue Fox-Euler formula for a crossed homomorphism.
theorem residueFreeGroupFoxBoundary_derivativeVector
(n : ℕ) (ψ : FreeGroup X →* H) (w : FreeGroup X) :
residueFreeGroupFoxBoundary n ψ
(residueFreeGroupFoxDerivativeVector n ψ w) =
residueGroupRingBoundary n ψ wBoundary-map form of the residue Fox fundamental formula.
Show Lean proof
by
let beta : ScalarCrossedHom (residueGroupRingScalar n ψ) (ResidueGroupRing n H) :=
(residueFreeGroupFoxDerivativeVector n ψ).mapLinear
(residueFreeGroupFoxBoundary n ψ)
have hbasis :
∀ x : X, beta (FreeGroup.of x) =
residueGroupRingBoundary n ψ (FreeGroup.of x) := by
intro x
simp only [beta, ScalarCrossedHom.mapLinear_apply,
residueFreeGroupFoxDerivativeVector_of, residueFreeGroupFoxBoundary_single]
have hbeta_eq :
beta =
freeCrossedHomWithCoeff
(A := ResidueGroupRing n H)
(residueGroupRingScalar n ψ)
(fun x => residueGroupRingBoundary n ψ (FreeGroup.of x)) := by
exact freeCrossedHomWithCoeff_unique
(A := ResidueGroupRing n H)
(residueGroupRingScalar n ψ)
(fun x => residueGroupRingBoundary n ψ (FreeGroup.of x)) beta hbasis
have hboundary_eq :
residueGroupRingBoundary n ψ =
freeCrossedHomWithCoeff
(A := ResidueGroupRing n H)
(residueGroupRingScalar n ψ)
(fun x => residueGroupRingBoundary n ψ (FreeGroup.of x)) := by
exact freeCrossedHomWithCoeff_unique
(A := ResidueGroupRing n H)
(residueGroupRingScalar n ψ)
(fun x => residueGroupRingBoundary n ψ (FreeGroup.of x))
(residueGroupRingBoundary n ψ) (by intro x; rfl)
exact congrArg
(fun d : ScalarCrossedHom (residueGroupRingScalar n ψ) (ResidueGroupRing n H) => d w)
(hbeta_eq.trans hboundary_eq.symm)
theorem residueFreeGroupFoxBoundary_of_crossedHom
(n : ℕ) (ψ : FreeGroup X →* H)
(delta : ScalarCrossedHom (residueGroupRingScalar n ψ)
(ResidueFreeFoxCoordinates n H X))
(hbasis :
∀ x : X, delta (FreeGroup.of x) =
Pi.single x (1 : ResidueGroupRing n H))
(w : FreeGroup X) :
residueFreeGroupFoxBoundary n ψ (delta w) =
residueGroupRingBoundary n ψ wAny residue crossed homomorphism with the standard basis values satisfies the residue Fox boundary formula.
Show Lean proof
by
have hdelta_eq :
delta = residueFreeGroupFoxDerivativeVector n ψ :=
residueFreeGroupFoxDerivativeVector_unique n ψ delta hbasis
rw [hdelta_eq]
exact residueFreeGroupFoxBoundary_derivativeVector n ψ w
theorem residueFreeGroupFoxDerivative_fundamental_formula_of_crossedHom
(n : ℕ) (ψ : FreeGroup X →* H)
(delta : ScalarCrossedHom (residueGroupRingScalar n ψ)
(ResidueFreeFoxCoordinates n H X))
(hbasis :
∀ x : X, delta (FreeGroup.of x) =
Pi.single x (1 : ResidueGroupRing n H))
(w : FreeGroup X) :
residueGroupRingBoundary n ψ w =
∑ i : X,
delta w i *
(MonoidAlgebra.of (ModNCompletedCoeff n) H (ψ (FreeGroup.of i)) - 1)The residue Fox-Euler sum computed from a crossed homomorphism with standard basis values is \([\psi(w)]-1\).
Show Lean proof
by
simpa [residueFreeGroupFoxBoundary_apply] using
(residueFreeGroupFoxBoundary_of_crossedHom n ψ delta hbasis w).symm
theorem residueFreeGroupFoxDerivative_euler_formula_of_crossedHom
(n : ℕ) (ψ : FreeGroup X →* H)
(delta : ScalarCrossedHom (residueGroupRingScalar n ψ)
(ResidueFreeFoxCoordinates n H X))
(hbasis :
∀ x : X, delta (FreeGroup.of x) =
Pi.single x (1 : ResidueGroupRing n H))
(w : FreeGroup X) :
(MonoidAlgebra.of (ModNCompletedCoeff n) H (ψ w) : ResidueGroupRing n H) - 1 =
∑ i : X,
delta w i *
(MonoidAlgebra.of (ModNCompletedCoeff n) H (ψ (FreeGroup.of i)) - 1)The explicit \([\psi(w)]-1\) form of the residue Fox-Euler formula for a crossed homomorphism.
Show Lean proof
by
have h := residueFreeGroupFoxDerivative_fundamental_formula_of_crossedHom
n ψ delta hbasis w
change (MonoidAlgebra.of (ModNCompletedCoeff n) H (ψ w) :
ResidueGroupRing n H) - 1 = _ at h
exact h
theorem residueFreeGroupFoxDerivative_fundamental_formula
(n : ℕ) (ψ : FreeGroup X →* H) (w : FreeGroup X) :
residueGroupRingBoundary n ψ w =
∑ i : X,
residueFreeGroupFoxDerivative n ψ i w *
(MonoidAlgebra.of (ModNCompletedCoeff n) H (ψ (FreeGroup.of i)) - 1)The residue Fox fundamental formula, also known as the residue Fox-Euler formula: \([\psi(w)]-1 = \sum_i (\partial w/\partial x_i)([\psi(x_i)]-1)\).
Show Lean proof
by
simpa [residueFreeGroupFoxBoundary_apply, residueFreeGroupFoxDerivative] using
(residueFreeGroupFoxBoundary_derivativeVector n ψ w).symm
theorem residueFreeGroupFoxDerivative_euler_formula
(n : ℕ) (ψ : FreeGroup X →* H) (w : FreeGroup X) :
(MonoidAlgebra.of (ModNCompletedCoeff n) H (ψ w) : ResidueGroupRing n H) - 1 =
∑ i : X,
residueFreeGroupFoxDerivative n ψ i w *
(MonoidAlgebra.of (ModNCompletedCoeff n) H (ψ (FreeGroup.of i)) - 1)The explicit \([\psi(w)]-1\) form of the residue Fox-Euler formula.
Show Lean proof
by
have h := residueFreeGroupFoxDerivative_fundamental_formula n ψ w
change (MonoidAlgebra.of (ModNCompletedCoeff n) H (ψ w) :
ResidueGroupRing n H) - 1 = _ at h
exact h