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Mathlib.Data.Fintype.Prod

fintype instance for the product of two fintypes. #

theorem Set.toFinset_prod {α : Type u_1} {β : Type u_2} (s : Set α) (t : Set β) [Fintype s] [Fintype t] [Fintype ↑(s ×ˢ t)] :
instance instFintypeProd (α : Type u_4) (β : Type u_5) [Fintype α] [Fintype β] :
Fintype (α × β)
Equations
@[simp]
theorem Finset.univ_product_univ {α : Type u_4} {β : Type u_5} [Fintype α] [Fintype β] :
Finset.univ ×ˢ Finset.univ = Finset.univ
@[simp]
theorem Fintype.card_prod (α : Type u_4) (β : Type u_5) [Fintype α] [Fintype β] :
@[simp]
theorem infinite_prod {α : Type u_1} {β : Type u_2} :
instance Pi.infinite_of_left {ι : Sort u_4} {π : ιType u_5} [∀ (i : ι), Nontrivial (π i)] [Infinite ι] :
Infinite ((i : ι) → π i)
Equations
theorem Pi.infinite_of_exists_right {ι : Type u_4} {π : ιType u_5} (i : ι) [Infinite (π i)] [∀ (i : ι), Nonempty (π i)] :
Infinite ((i : ι) → π i)

If at least one π i is infinite and the rest nonempty, the pi type of all π is infinite.

instance Pi.infinite_of_right {ι : Type u_4} {π : ιType u_5} [∀ (i : ι), Infinite (π i)] [Nonempty ι] :
Infinite ((i : ι) → π i)

See Pi.infinite_of_exists_right for the case that only one π i is infinite.

Equations