Lemmas about Vector.zip, Vector.zipWith, Vector.zipWithAll, and Vector.unzip.

Zippers

zipWith

theorem Vector.zipWith_comm {α : Type u_1} {β : Type u_2} {γ : Type u_3} {n : Nat} {f : α → β → γ} {as : Vector α n} {bs : Vector β n} : zipWith f as bs = zipWith (fun (b : β) (a : α) => f a b) bs as

theorem Vector.zipWith_comm_of_comm {α : Type u_1} {β : Type u_2} {n : Nat} {f : α → α → β} (comm : ∀ (x y : α), f x y = f y x) {xs ys : Vector α n} : zipWith f xs ys = zipWith f ys xs

@[simp]

theorem Vector.zipWith_self {α : Type u_1} {δ : Type u_2} {n : Nat} {f : α → α → δ} {xs : Vector α n} : zipWith f xs xs = map (fun (a : α) => f a a) xs

theorem Vector.getElem?_zipWith {α : Type u_1} {β : Type u_2} {γ : Type u_3} {n✝ : Nat} {as : Vector α n✝} {bs : Vector β n✝} {f : α → β → γ} {i : Nat} : (zipWith f as bs)[i]? = match as[i]?, bs[i]? with | some a, some b => some (f a b) | x, x_1 => none

See also getElem?_zipWith' for a variant using Option.map and Option.bind rather than a match.

theorem Vector.getElem?_zipWith' {α : Type u_1} {β : Type u_2} {γ : Type u_3} {n✝ : Nat} {as : Vector α n✝} {bs : Vector β n✝} {f : α → β → γ} {i : Nat} : (zipWith f as bs)[i]? = (Option.map f as[i]?).bind fun (g : β → γ) => Option.map g bs[i]?

Variant of getElem?_zipWith using Option.map and Option.bind rather than a match.

theorem Vector.getElem?_zipWith_eq_some {α : Type u_1} {β : Type u_2} {γ : Type u_3} {n : Nat} {f : α → β → γ} {as : Vector α n} {bs : Vector β n} {z : γ} {i : Nat} : (zipWith f as bs)[i]? = some z ↔ ∃ (x : α), ∃ (y : β), as[i]? = some x ∧ bs[i]? = some y ∧ f x y = z

theorem Vector.getElem?_zip_eq_some {α : Type u_1} {n : Nat} {β : Type u_2} {as : Vector α n} {bs : Vector β n} {z : α × β} {i : Nat} : (as.zip bs)[i]? = some z ↔ as[i]? = some z.fst ∧ bs[i]? = some z.snd

@[simp]

theorem Vector.zipWith_map {γ : Type u_1} {δ : Type u_2} {α : Type u_3} {β : Type u_4} {n : Nat} {μ : Type u_5} {f : γ → δ → μ} {g : α → γ} {h : β → δ} {as : Vector α n} {bs : Vector β n} : zipWith f (map g as) (map h bs) = zipWith (fun (a : α) (b : β) => f (g a) (h b)) as bs

theorem Vector.zipWith_map_left {α : Type u_1} {n : Nat} {β : Type u_2} {α' : Type u_3} {γ : Type u_4} {as : Vector α n} {bs : Vector β n} {f : α → α'} {g : α' → β → γ} : zipWith g (map f as) bs = zipWith (fun (a : α) (b : β) => g (f a) b) as bs

theorem Vector.zipWith_map_right {α : Type u_1} {n : Nat} {β : Type u_2} {β' : Type u_3} {γ : Type u_4} {as : Vector α n} {bs : Vector β n} {f : β → β'} {g : α → β' → γ} : zipWith g as (map f bs) = zipWith (fun (a : α) (b : β) => g a (f b)) as bs

theorem Vector.zipWith_foldr_eq_zip_foldr {α : Type u_1} {β : Type u_2} {γ : Type u_3} {δ : Type u_4} {n✝ : Nat} {as : Vector α n✝} {bs : Vector β n✝} {g : γ → δ → δ} {f : α → β → γ} {i : δ} : foldr g i (zipWith f as bs) = foldr (fun (p : α × β) (r : δ) => g (f p.fst p.snd) r) i (as.zip bs)

theorem Vector.zipWith_foldl_eq_zip_foldl {α : Type u_1} {β : Type u_2} {γ : Type u_3} {δ : Type u_4} {n✝ : Nat} {as : Vector α n✝} {bs : Vector β n✝} {g : δ → γ → δ} {f : α → β → γ} {i : δ} : foldl g i (zipWith f as bs) = foldl (fun (r : δ) (p : α × β) => g r (f p.fst p.snd)) i (as.zip bs)

theorem Vector.map_zipWith {α : Type u_1} {β : Type u_2} {γ : Type u_3} {n : Nat} {δ : Type u_4} {f : α → β} {g : γ → δ → α} {as : Vector γ n} {bs : Vector δ n} : map f (zipWith g as bs) = zipWith (fun (x : γ) (y : δ) => f (g x y)) as bs

theorem Vector.take_zipWith {α✝ : Type u_1} {α✝¹ : Type u_2} {α✝² : Type u_3} {f : α✝ → α✝¹ → α✝²} {n✝ : Nat} {as : Vector α✝ n✝} {bs : Vector α✝¹ n✝} {i : Nat} : (zipWith f as bs).take i = zipWith f (as.take i) (bs.take i)

theorem Vector.extract_zipWith {α✝ : Type u_1} {α✝¹ : Type u_2} {α✝² : Type u_3} {f : α✝ → α✝¹ → α✝²} {n✝ : Nat} {as : Vector α✝ n✝} {bs : Vector α✝¹ n✝} {i j : Nat} : (zipWith f as bs).extract i j = zipWith f (as.extract i j) (bs.extract i j)

theorem Vector.zipWith_append {α : Type u_1} {β : Type u_2} {γ : Type u_3} {n m : Nat} {f : α → β → γ} {as : Vector α n} {as' : Vector α m} {bs : Vector β n} {bs' : Vector β m} : zipWith f (as ++ as') (bs ++ bs') = zipWith f as bs ++ zipWith f as' bs'

theorem Vector.zipWith_eq_append_iff {α : Type u_1} {β : Type u_2} {γ : Type u_3} {n m : Nat} {xs : Vector γ n} {ys : Vector γ m} {f : α → β → γ} {as : Vector α (n + m)} {bs : Vector β (n + m)} : zipWith f as bs = xs ++ ys ↔ ∃ (as₁ : Vector α n), ∃ (as₂ : Vector α m), ∃ (bs₁ : Vector β n), ∃ (bs₂ : Vector β m), as = as₁ ++ as₂ ∧ bs = bs₁ ++ bs₂ ∧ xs = zipWith f as₁ bs₁ ∧ ys = zipWith f as₂ bs₂

@[simp]

theorem Vector.zipWith_replicate {α : Type u_1} {β : Type u_2} {α✝ : Type u_3} {f : α → β → α✝} {a : α} {b : β} {n : Nat} : zipWith f (replicate n a) (replicate n b) = replicate n (f a b)

@[reducible, inline, deprecated Vector.zipWith_replicate (since := "2025-03-18")]

abbrev Vector.zipWith_mkVector {α : Type u_1} {β : Type u_2} {α✝ : Type u_3} {f : α → β → α✝} {a : α} {b : β} {n : Nat} : zipWith f (replicate n a) (replicate n b) = replicate n (f a b)

Equations

• @Vector.zipWith_mkVector = @Vector.zipWith_replicate

theorem Vector.map_uncurry_zip_eq_zipWith {α : Type u_1} {β : Type u_2} {γ : Type u_3} {n : Nat} {f : α → β → γ} {as : Vector α n} {bs : Vector β n} : map (Function.uncurry f) (as.zip bs) = zipWith f as bs

theorem Vector.map_zip_eq_zipWith {α : Type u_1} {β : Type u_2} {γ : Type u_3} {n : Nat} {f : α × β → γ} {as : Vector α n} {bs : Vector β n} : map f (as.zip bs) = zipWith (Function.curry f) as bs

theorem Vector.reverse_zipWith {α : Type u_1} {β : Type u_2} {γ : Type u_3} {n : Nat} {f : α → β → γ} {as : Vector α n} {bs : Vector β n} : (zipWith f as bs).reverse = zipWith f as.reverse bs.reverse

zip

@[simp]

theorem Vector.getElem_zip {α : Type u_1} {n : Nat} {β : Type u_2} {as : Vector α n} {bs : Vector β n} {i : Nat} {h : i < n} : (as.zip bs)[i] = (as[i], bs[i])

theorem Vector.zip_eq_zipWith {α : Type u_1} {n : Nat} {β : Type u_2} {as : Vector α n} {bs : Vector β n} : as.zip bs = zipWith Prod.mk as bs

theorem Vector.zip_map {α : Type u_1} {γ : Type u_2} {β : Type u_3} {δ : Type u_4} {n : Nat} {f : α → γ} {g : β → δ} {as : Vector α n} {bs : Vector β n} : (map f as).zip (map g bs) = map (Prod.map f g) (as.zip bs)

theorem Vector.zip_map_left {α : Type u_1} {γ : Type u_2} {n : Nat} {β : Type u_3} {f : α → γ} {as : Vector α n} {bs : Vector β n} : (map f as).zip bs = map (Prod.map f id) (as.zip bs)

theorem Vector.zip_map_right {β : Type u_1} {γ : Type u_2} {α : Type u_3} {n : Nat} {f : β → γ} {as : Vector α n} {bs : Vector β n} : as.zip (map f bs) = map (Prod.map id f) (as.zip bs)

theorem Vector.zip_append {α : Type u_1} {n : Nat} {β : Type u_2} {m : Nat} {as : Vector α n} {bs : Vector β n} {as' : Vector α m} {bs' : Vector β m} : (as ++ as').zip (bs ++ bs') = as.zip bs ++ as'.zip bs'

theorem Vector.zip_map' {α : Type u_1} {β : Type u_2} {γ : Type u_3} {n : Nat} {f : α → β} {g : α → γ} {xs : Vector α n} : (map f xs).zip (map g xs) = map (fun (a : α) => (f a, g a)) xs

theorem Vector.of_mem_zip {α : Type u_1} {n : Nat} {β : Type u_2} {a : α} {b : β} {as : Vector α n} {bs : Vector β n} : (a, b) ∈ as.zip bs → a ∈ as ∧ b ∈ bs

theorem Vector.map_fst_zip {α : Type u_1} {n : Nat} {β : Type u_2} (as : Vector α n) {bs : Vector β n} : map Prod.fst (as.zip bs) = as

theorem Vector.map_snd_zip {α : Type u_1} {n : Nat} {β : Type u_2} {as : Vector α n} (bs : Vector β n) : map Prod.snd (as.zip bs) = bs

theorem Vector.map_prod_left_eq_zip {α : Type u_1} {n : Nat} {β : Type u_2} {xs : Vector α n} {f : α → β} : map (fun (x : α) => (x, f x)) xs = xs.zip (map f xs)

theorem Vector.map_prod_right_eq_zip {α : Type u_1} {n : Nat} {β : Type u_2} {xs : Vector α n} {f : α → β} : map (fun (x : α) => (f x, x)) xs = (map f xs).zip xs

theorem Vector.zip_eq_append_iff {α : Type u_1} {n m : Nat} {β : Type u_2} {as : Vector α (n + m)} {bs : Vector β (n + m)} {xs : Vector (α × β) n} {ys : Vector (α × β) m} : as.zip bs = xs ++ ys ↔ ∃ (as₁ : Vector α n), ∃ (as₂ : Vector α m), ∃ (bs₁ : Vector β n), ∃ (bs₂ : Vector β m), as₁.size = bs₁.size ∧ as = as₁ ++ as₂ ∧ bs = bs₁ ++ bs₂ ∧ xs = as₁.zip bs₁ ∧ ys = as₂.zip bs₂

@[simp]

theorem Vector.zip_replicate {α : Type u_1} {β : Type u_2} {a : α} {b : β} {n : Nat} : (replicate n a).zip (replicate n b) = replicate n (a, b)

@[reducible, inline, deprecated Vector.zip_replicate (since := "2025-03-18")]

abbrev Vector.zip_mkVector {α : Type u_1} {β : Type u_2} {a : α} {b : β} {n : Nat} : (replicate n a).zip (replicate n b) = replicate n (a, b)

Equations

• @Vector.zip_mkVector = @Vector.zip_replicate

unzip

@[simp]

theorem Vector.unzip_fst {α✝ : Type u_1} {β✝ : Type u_2} {n✝ : Nat} {xs : Vector (α✝ × β✝) n✝} : xs.unzip.fst = map Prod.fst xs

@[simp]

theorem Vector.unzip_snd {α✝ : Type u_1} {β✝ : Type u_2} {n✝ : Nat} {xs : Vector (α✝ × β✝) n✝} : xs.unzip.snd = map Prod.snd xs

theorem Vector.unzip_eq_map {α : Type u_1} {β : Type u_2} {n : Nat} {xs : Vector (α × β) n} : xs.unzip = (map Prod.fst xs, map Prod.snd xs)

theorem Vector.zip_unzip {α : Type u_1} {β : Type u_2} {n : Nat} (xs : Vector (α × β) n) : xs.unzip.fst.zip xs.unzip.snd = xs

theorem Vector.unzip_zip_left {α : Type u_1} {n : Nat} {β : Type u_2} {as : Vector α n} {bs : Vector β n} : (as.zip bs).unzip.fst = as

theorem Vector.unzip_zip_right {α : Type u_1} {n : Nat} {β : Type u_2} {as : Vector α n} {bs : Vector β n} : (as.zip bs).unzip.snd = bs

theorem Vector.unzip_zip {α : Type u_1} {n : Nat} {β : Type u_2} {as : Vector α n} {bs : Vector β n} : (as.zip bs).unzip = (as, bs)

theorem Vector.zip_of_prod {α : Type u_1} {n : Nat} {β : Type u_2} {as : Vector α n} {bs : Vector β n} {xs : Vector (α × β) n} (hl : map Prod.fst xs = as) (hr : map Prod.snd xs = bs) : xs = as.zip bs

@[simp]

theorem Vector.unzip_replicate {α : Type u_1} {β : Type u_2} {a : α} {b : β} {n : Nat} : (replicate n (a, b)).unzip = (replicate n a, replicate n b)

@[reducible, inline, deprecated Vector.unzip_replicate (since := "2025-03-18")]

abbrev Vector.unzip_mkVector {α : Type u_1} {β : Type u_2} {a : α} {b : β} {n : Nat} : (replicate n (a, b)).unzip = (replicate n a, replicate n b)

Equations

• @Vector.unzip_mkVector = @Vector.unzip_replicate