Finiteness lemmas for pointwise operations on sets #
@[instance_reducible]
instance Set.fintypeMul {α : Type u_1} [Mul α] [DecidableEq α] (s t : Set α) [Fintype ↑s] [Fintype ↑t] :
Multiplication preserves finiteness.
@[instance_reducible]
instance Set.fintypeAdd {α : Type u_1} [Add α] [DecidableEq α] (s t : Set α) [Fintype ↑s] [Fintype ↑t] :
Addition preserves finiteness.
@[instance_reducible]
instance Set.decidableMemMul {α : Type u_1} [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
@[instance_reducible]
instance Set.decidableMemAdd {α : Type u_1} [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
@[instance_reducible]
instance Set.decidableMemPow {α : Type u_1} [Monoid α] {s : Set α} [Fintype α] [DecidableEq α] [DecidablePred fun (x : α) => x ∈ s] (n : ℕ) :
DecidablePred fun (x : α) => x ∈ s ^ n
@[instance_reducible]
instance Set.decidableMemNSMul {α : Type u_1} [AddMonoid α] {s : Set α} [Fintype α] [DecidableEq α] [DecidablePred fun (x : α) => x ∈ s] (n : ℕ) :
DecidablePred fun (x : α) => x ∈ n • s
@[simp]
@[simp]
@[simp]
@[simp]
Alias of the forward direction of Set.finite_inv.
Alias of the reverse direction of Set.finite_inv.
Alias of the reverse direction of Set.finite_neg.
Alias of the forward direction of Set.finite_neg.
@[instance_reducible]
instance Set.fintypeDiv {α : Type u_1} [Div α] [DecidableEq α] (s t : Set α) [Fintype ↑s] [Fintype ↑t] :
Division preserves finiteness.
@[instance_reducible]
instance Set.fintypeSub {α : Type u_1} [Sub α] [DecidableEq α] (s t : Set α) [Fintype ↑s] [Fintype ↑t] :
Subtraction preserves finiteness.
theorem Group.card_pow_eq_card_pow_card_univ {G : Type u_3} [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_3} [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)