Pointwise instances on Subgroup
and AddSubgroup
s #
This file provides the actions
which matches the action of Set.mulActionSet
.
These actions are available in the Pointwise
locale.
Implementation notes #
The pointwise section of this file is almost identical to
the file Mathlib.Algebra.Group.Submonoid.Pointwise
.
Where possible, try to keep them in sync.
For subgroups generated by a single element, see the simpler zpow_induction_left
.
For additive subgroups generated by a single element, see the simpler
zsmul_induction_left
.
For subgroups generated by a single element, see the simpler zpow_induction_right
.
For additive subgroups generated by a single element, see the simpler
zsmul_induction_right
.
An induction principle for closure membership. If p
holds for 1
and all elements of
k
and their inverse, and is preserved under multiplication, then p
holds for all elements of
the closure of k
.
An induction principle for additive closure membership. If p
holds for 0
and all
elements of k
and their negation, and is preserved under addition, then p
holds for all
elements of the additive closure of k
.
An induction principle for elements of ⨆ i, S i
.
If C
holds for 1
and all elements of S i
for all i
, and is preserved under multiplication,
then it holds for all elements of the supremum of S
.
An induction principle for elements of ⨆ i, S i
.
If C
holds for 0
and all elements of S i
for all i
, and is preserved under addition,
then it holds for all elements of the supremum of S
.
A dependent version of Subgroup.iSup_induction
.
A dependent version of AddSubgroup.iSup_induction
.
The carrier of H ⊔ N
is just ↑H + ↑N
(pointwise set addition)
when N
is normal.
The carrier of N ⊔ H
is just ↑N + ↑H
(pointwise set addition)
when N
is normal.
Pointwise action #
The action on a subgroup corresponding to applying the action to every element.
This is available as an instance in the Pointwise
locale.
Equations
Instances For
Applying a MulDistribMulAction
results in an isomorphic subgroup
Equations
- Subgroup.equivSMul a H = (MulDistribMulAction.toMulEquiv G a).subgroupMap H
Instances For
The action on an additive subgroup corresponding to applying the action to every element.
This is available as an instance in the Pointwise
locale.
Equations
Instances For
For additive subgroups S
and T
of a ring, the product of S
and T
as submonoids
is automatically a subgroup, which we define as the product of S
and T
as subgroups.
Equations
- AddSubgroup.mul = { mul := fun (M N : AddSubgroup R) => let __spread.0 := M.toAddSubmonoid * N.toAddSubmonoid; { toAddSubmonoid := __spread.0, neg_mem' := ⋯ } }