Finiteness lemmas for pointwise operations on sets #
instance
Set.fintypeMul
{α : Type u_2}
[Mul α]
[DecidableEq α]
(s t : Set α)
[Fintype ↑s]
[Fintype ↑t]
:
Multiplication preserves finiteness.
Equations
instance
Set.fintypeAdd
{α : Type u_2}
[Add α]
[DecidableEq α]
(s t : Set α)
[Fintype ↑s]
[Fintype ↑t]
:
Addition preserves finiteness.
Equations
instance
Set.decidableMemMul
{α : Type u_2}
[Monoid α]
{s t : Set α}
[Fintype α]
[DecidableEq α]
[DecidablePred fun (x : α) => x ∈ s]
[DecidablePred fun (x : α) => x ∈ t]
:
DecidablePred fun (x : α) => x ∈ s * t
Equations
instance
Set.decidableMemAdd
{α : Type u_2}
[AddMonoid α]
{s t : Set α}
[Fintype α]
[DecidableEq α]
[DecidablePred fun (x : α) => x ∈ s]
[DecidablePred fun (x : α) => x ∈ t]
:
DecidablePred fun (x : α) => x ∈ s + t
Equations
instance
Set.decidableMemPow
{α : Type u_2}
[Monoid α]
{s : Set α}
[Fintype α]
[DecidableEq α]
[DecidablePred fun (x : α) => x ∈ s]
(n : ℕ)
:
DecidablePred fun (x : α) => x ∈ s ^ n
Equations
instance
Set.decidableMemNSMul
{α : Type u_2}
[AddMonoid α]
{s : Set α}
[Fintype α]
[DecidableEq α]
[DecidablePred fun (x : α) => x ∈ s]
(n : ℕ)
:
DecidablePred fun (x : α) => x ∈ n • s
Equations
@[simp]
@[simp]
@[simp]
@[simp]
Alias of the reverse direction of Set.finite_inv
.
Alias of the forward direction of Set.finite_inv
.
instance
Set.fintypeDiv
{α : Type u_2}
[Div α]
[DecidableEq α]
(s t : Set α)
[Fintype ↑s]
[Fintype ↑t]
:
Division preserves finiteness.
Equations
instance
Set.fintypeSub
{α : Type u_2}
[Sub α]
[DecidableEq α]
(s t : Set α)
[Fintype ↑s]
[Fintype ↑t]
:
Subtraction preserves finiteness.
Equations
theorem
Group.card_pow_eq_card_pow_card_univ
{G : Type u_5}
[Group G]
[Fintype G]
(S : Set G)
[(k : ℕ) → DecidablePred fun (x : G) => x ∈ S ^ k]
(k : ℕ)
:
Fintype.card G ≤ k → Fintype.card ↑(S ^ k) = Fintype.card ↑(S ^ Fintype.card G)
theorem
AddGroup.card_nsmul_eq_card_nsmul_card_univ
{G : Type u_5}
[AddGroup G]
[Fintype G]
(S : Set G)
[(k : ℕ) → DecidablePred fun (x : G) => x ∈ k • S]
(k : ℕ)
:
Fintype.card G ≤ k → Fintype.card ↑(k • S) = Fintype.card ↑(Fintype.card G • S)