ProCGroups.FoxDifferential.Completed.CoefficientRings.CompletedGroupAlgebraPrimePower.InClass.System.Ring.GroupLike
The principal declarations in this module are:
primePowerCompletedGroupAlgebraOfInClassThe class-restricted completed group-algebra element represented by a group element. -primePowerCompletedGroupAlgebraProjectionInClass_ofThe \(C\)-indexed prime-power completed group-algebra projection sends a group-like element to its finite-stage group-like class. -primePowerCompletedGroupAlgebraOfInClass_oneThe canonical map to the class-indexed prime-power completed group algebra sends \(1\) to \(1\). -primePowerCompletedGroupAlgebraOfInClass_mulThe canonical map to the class-indexed prime-power completed group algebra preserves multiplication.
def primePowerCompletedGroupAlgebraOfInClass
(ell : Nat)
{H : Type u} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
(C : ProCGroups.FiniteGroupClass.{u}) (h : H) :
PrimePowerCompletedGroupAlgebraInClass ell H C := by
refine ⟨fun i => ?_, ?_⟩
· exact
MonoidAlgebra.of (ModNCompletedCoeff (ell ^ i.1))
(CompletedGroupAlgebraQuotientInClass H C i.2)
(QuotientGroup.mk h)
· intro i j hij
change primePowerCompletedGroupAlgebraTransitionInClass (ℓ := ell) (G := H) C hij
(MonoidAlgebra.of (ModNCompletedCoeff (ell ^ j.1))
(CompletedGroupAlgebraQuotientInClass H C j.2)
(QuotientGroup.mk h)) =
MonoidAlgebra.of (ModNCompletedCoeff (ell ^ i.1))
(CompletedGroupAlgebraQuotientInClass H C i.2)
(QuotientGroup.mk h)
rw [primePowerCompletedGroupAlgebraTransitionInClass_of]
rflThe class-restricted completed group-algebra element represented by a group element.
@[simp]
theorem primePowerCompletedGroupAlgebraProjectionInClass_of
(ell : Nat)
{H : Type u} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
(C : ProCGroups.FiniteGroupClass.{u}) (i : PrimePowerCompletedGroupAlgebraIndexInClass H C)
(h : H) :
primePowerCompletedGroupAlgebraProjectionInClass (ℓ := ell) (G := H) C i
(primePowerCompletedGroupAlgebraOfInClass (ell := ell) C h) =
MonoidAlgebra.of (ModNCompletedCoeff (ell ^ i.1))
(CompletedGroupAlgebraQuotientInClass H C i.2)
(QuotientGroup.mk h)The \(C\)-indexed prime-power completed group-algebra projection sends a group-like element to its finite-stage group-like class.
Show Lean proof
by
rfl
@[simp]
theorem primePowerCompletedGroupAlgebraOfInClass_one
(ell : Nat)
{H : Type u} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
(C : ProCGroups.FiniteGroupClass.{u}) :
primePowerCompletedGroupAlgebraOfInClass (ell := ell) (H := H) C 1 = 1The canonical map to the class-indexed prime-power completed group algebra sends \(1\) to \(1\).
Show Lean proof
by
apply Subtype.ext
funext i
change primePowerCompletedGroupAlgebraProjectionInClass (ℓ := ell) (G := H) C i
(primePowerCompletedGroupAlgebraOfInClass (ell := ell) (H := H) C 1) =
primePowerCompletedGroupAlgebraProjectionInClass (ℓ := ell) (G := H) C i
(1 : PrimePowerCompletedGroupAlgebraInClass ell H C)
rw [primePowerCompletedGroupAlgebraProjectionInClass_of,
primePowerCompletedGroupAlgebraProjectionInClass_one]
exact map_one
(MonoidAlgebra.of (ModNCompletedCoeff (ell ^ i.1))
(CompletedGroupAlgebraQuotientInClass H C i.2))
@[simp]
theorem primePowerCompletedGroupAlgebraOfInClass_mul
(ell : Nat)
{H : Type u} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
(C : ProCGroups.FiniteGroupClass.{u}) (h₁ h₂ : H) :
primePowerCompletedGroupAlgebraOfInClass (ell := ell) C (h₁ * h₂) =
primePowerCompletedGroupAlgebraOfInClass (ell := ell) C h₁ *
primePowerCompletedGroupAlgebraOfInClass (ell := ell) C h₂The canonical map to the class-indexed prime-power completed group algebra preserves multiplication.
Show Lean proof
by
apply Subtype.ext
funext i
change primePowerCompletedGroupAlgebraProjectionInClass (ℓ := ell) (G := H) C i
(primePowerCompletedGroupAlgebraOfInClass (ell := ell) C (h₁ * h₂)) =
primePowerCompletedGroupAlgebraProjectionInClass (ℓ := ell) (G := H) C i
(primePowerCompletedGroupAlgebraOfInClass (ell := ell) C h₁ *
primePowerCompletedGroupAlgebraOfInClass (ell := ell) C h₂)
rw [primePowerCompletedGroupAlgebraProjectionInClass_of,
primePowerCompletedGroupAlgebraProjectionInClass_mul,
primePowerCompletedGroupAlgebraProjectionInClass_of,
primePowerCompletedGroupAlgebraProjectionInClass_of]
change
(MonoidAlgebra.of (ModNCompletedCoeff (ell ^ i.1))
(CompletedGroupAlgebraQuotientInClass H C i.2))
(QuotientGroup.mk (h₁ * h₂)) =
(MonoidAlgebra.of (ModNCompletedCoeff (ell ^ i.1))
(CompletedGroupAlgebraQuotientInClass H C i.2))
(QuotientGroup.mk h₁) *
(MonoidAlgebra.of (ModNCompletedCoeff (ell ^ i.1))
(CompletedGroupAlgebraQuotientInClass H C i.2))
(QuotientGroup.mk h₂)
rw [QuotientGroup.mk_mul]
exact map_mul
(MonoidAlgebra.of (ModNCompletedCoeff (ell ^ i.1))
(CompletedGroupAlgebraQuotientInClass H C i.2))
(QuotientGroup.mk h₁) (QuotientGroup.mk h₂)