Lemmas about group actions on big operators #
Note that analogous lemmas for Module
s like Finset.sum_smul
appear in other files.
theorem
Multiset.smul_sum
{α : Type u_1}
{β : Type u_2}
[AddCommMonoid β]
[DistribSMul α β]
{r : α}
{s : Multiset β}
:
r • Multiset.sum s = Multiset.sum (Multiset.map (fun (x : β) => r • x) s)
theorem
Finset.smul_sum
{α : Type u_1}
{β : Type u_2}
{γ : Type u_3}
[AddCommMonoid β]
[DistribSMul α β]
{r : α}
{f : γ → β}
{s : Finset γ}
:
(r • Finset.sum s fun (x : γ) => f x) = Finset.sum s fun (x : γ) => r • f x
theorem
Multiset.smul_prod
{α : Type u_1}
{β : Type u_2}
[Monoid α]
[CommMonoid β]
[MulDistribMulAction α β]
{r : α}
{s : Multiset β}
:
r • Multiset.prod s = Multiset.prod (Multiset.map (fun (x : β) => r • x) s)
theorem
Finset.smul_prod
{α : Type u_1}
{β : Type u_2}
{γ : Type u_3}
[Monoid α]
[CommMonoid β]
[MulDistribMulAction α β]
{r : α}
{f : γ → β}
{s : Finset γ}
:
(r • Finset.prod s fun (x : γ) => f x) = Finset.prod s fun (x : γ) => r • f x