Documentation

Init.Data.Prod

instance Prod.instLawfulBEq {α : Type u_1} {β : Type u_2} [BEq α] [BEq β] [LawfulBEq α] [LawfulBEq β] :
LawfulBEq (α × β)
Equations
  • =
@[simp]
theorem Prod.forall {α : Type u_1} {β : Type u_2} {p : α × βProp} :
(∀ (x : α × β), p x) ∀ (a : α) (b : β), p (a, b)
@[simp]
theorem Prod.exists {α : Type u_1} {β : Type u_2} {p : α × βProp} :
(∃ (x : α × β), p x) ∃ (a : α), ∃ (b : β), p (a, b)
@[simp]
theorem Prod.map_id {α : Type u_1} {β : Type u_2} :
Prod.map id id = id
@[simp]
theorem Prod.map_id' {α : Type u_1} {β : Type u_2} :
(Prod.map (fun (a : α) => a) fun (b : β) => b) = fun (x : α × β) => x
theorem Prod.map_comp_map {α : Type u_1} {β : Type u_2} {γ : Type u_3} {δ : Type u_4} {ε : Type u_5} {ζ : Type u_6} (f : αβ) (f' : γδ) (g : βε) (g' : δζ) :
Prod.map g g' Prod.map f f' = Prod.map (g f) (g' f')

Composing a Prod.map with another Prod.map is equal to a single Prod.map of composed functions.

theorem Prod.map_map {α : Type u_1} {β : Type u_2} {γ : Type u_3} {δ : Type u_4} {ε : Type u_5} {ζ : Type u_6} (f : αβ) (f' : γδ) (g : βε) (g' : δζ) (x : α × γ) :
Prod.map g g' (Prod.map f f' x) = Prod.map (g f) (g' f') x

Composing a Prod.map with another Prod.map is equal to a single Prod.map of composed functions, fully applied.

def Prod.swap {α : Type u_1} {β : Type u_2} :
α × ββ × α

Swap the factors of a product. swap (a, b) = (b, a)

Equations
  • p.swap = (p.snd, p.fst)
Instances For
    @[simp]
    theorem Prod.swap_swap {α : Type u_1} {β : Type u_2} (x : α × β) :
    x.swap.swap = x
    @[simp]
    theorem Prod.fst_swap {α : Type u_1} {β : Type u_2} {p : α × β} :
    p.swap.fst = p.snd
    @[simp]
    theorem Prod.snd_swap {α : Type u_1} {β : Type u_2} {p : α × β} :
    p.swap.snd = p.fst
    @[simp]
    theorem Prod.swap_prod_mk {α : Type u_1} {β : Type u_2} {a : α} {b : β} :
    (a, b).swap = (b, a)
    @[simp]
    theorem Prod.swap_swap_eq {α : Type u_1} {β : Type u_2} :
    Prod.swap Prod.swap = id
    @[simp]
    theorem Prod.swap_inj {α : Type u_1} {β : Type u_2} {p : α × β} {q : α × β} :
    p.swap = q.swap p = q
    theorem Prod.map_comp_swap {α : Type u_1} {β : Type u_2} {γ : Type u_3} {δ : Type u_4} (f : αβ) (g : γδ) :
    Prod.map f g Prod.swap = Prod.swap Prod.map g f

    For two functions f and g, the composition of Prod.map f g with Prod.swap is equal to the composition of Prod.swap with Prod.map g f.