Multiplicative and additive equivalence acting on units. #
An additive group is isomorphic to its group of additive units
Equations
Instances For
A multiplicative equivalence of monoids defines a multiplicative equivalence of their groups of units.
Equations
- Units.mapEquiv h = { toFun := (↑(Units.map h.toMonoidHom)).toFun, invFun := ⇑(Units.map h.symm.toMonoidHom), left_inv := ⋯, right_inv := ⋯, map_mul' := ⋯ }
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Left addition of an additive unit is a permutation of the underlying type.
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Left multiplication by a unit of a monoid is a permutation of the underlying type.
Equations
Instances For
Right addition of an additive unit is a permutation of the underlying type.
Equations
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Right multiplication by a unit of a monoid is a permutation of the underlying type.
Equations
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Left addition in an AddGroup
is a permutation of the underlying type.
Equations
- Equiv.addLeft a = (toAddUnits a).addLeft
Instances For
Left multiplication in a Group
is a permutation of the underlying type.
Equations
- Equiv.mulLeft a = (toUnits a).mulLeft
Instances For
Extra simp lemma that dsimp
can use. simp
will never use this.
Extra simp lemma that dsimp
can use. simp
will never use this.
Right addition in an AddGroup
is a permutation of the underlying type.
Equations
- Equiv.addRight a = (toAddUnits a).addRight
Instances For
Right multiplication in a Group
is a permutation of the underlying type.
Equations
- Equiv.mulRight a = (toUnits a).mulRight
Instances For
Extra simp lemma that dsimp
can use. simp
will never use this.
Extra simp lemma that dsimp
can use. simp
will never use this.
A version of Equiv.addLeft a (-b)
that is defeq to a - b
.
Equations
- Equiv.subLeft a = { toFun := fun (b : G) => a - b, invFun := fun (b : G) => -b + a, left_inv := ⋯, right_inv := ⋯ }
Instances For
A version of Equiv.mulLeft a b⁻¹
that is defeq to a / b
.
Equations
- Equiv.divLeft a = { toFun := fun (b : G) => a / b, invFun := fun (b : G) => b⁻¹ * a, left_inv := ⋯, right_inv := ⋯ }
Instances For
A version of Equiv.addRight (-a) b
that is defeq to b - a
.
Equations
- Equiv.subRight a = { toFun := fun (b : G) => b - a, invFun := fun (b : G) => b + a, left_inv := ⋯, right_inv := ⋯ }
Instances For
A version of Equiv.mulRight a⁻¹ b
that is defeq to b / a
.
Equations
- Equiv.divRight a = { toFun := fun (b : G) => b / a, invFun := fun (b : G) => b * a, left_inv := ⋯, right_inv := ⋯ }
Instances For
When the AddGroup
is commutative, Equiv.neg
is an AddEquiv
.
Equations
- AddEquiv.neg G = { toFun := Neg.neg, invFun := Neg.neg, left_inv := ⋯, right_inv := ⋯, map_add' := ⋯ }
Instances For
In a DivisionCommMonoid
, Equiv.inv
is a MulEquiv
. There is a variant of this
MulEquiv.inv' G : G ≃* Gᵐᵒᵖ
for the non-commutative case.
Equations
- MulEquiv.inv G = { toFun := Inv.inv, invFun := Inv.inv, left_inv := ⋯, right_inv := ⋯, map_mul' := ⋯ }