Additional theorems and definitions about the Vector type #
This file introduces the infix notation ::ᵥ for Vector.cons.
If a : α and l : Vector α n, then cons a l, is the vector of length n + 1
whose first element is a and with l as the rest of the list.
Equations
- Mathlib.Vector.«term_::ᵥ_» = Lean.ParserDescr.trailingNode `Mathlib.Vector.term_::ᵥ_ 67 68 (Lean.ParserDescr.binary `andthen (Lean.ParserDescr.symbol " ::ᵥ ") (Lean.ParserDescr.cat `term 67))
Instances For
Equations
- Mathlib.Vector.instInhabited = { default := Mathlib.Vector.ofFn default }
Two v w : Vector α n are equal iff they are equal at every single index.
The empty Vector is a Subsingleton.
Equations
- ⋯ = ⋯
The natural equivalence between length-n vectors and functions from Fin n.
Equations
- Equiv.vectorEquivFin α n = { toFun := Mathlib.Vector.get, invFun := Mathlib.Vector.ofFn, left_inv := ⋯, right_inv := ⋯ }
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The tail of a nil vector is nil.
The tail of a vector made up of one element is nil.
The list that makes up a Vector made up of a single element,
retrieved via toList, is equal to the list of that single element.
Mapping under id does not change a vector.
The List of a vector after a reverse, retrieved by toList is equal
to the List.reverse after retrieving a vector's toList.
The last element of a Vector, given that the vector is at least one element.
Instances For
The last element of a Vector, given that the vector is at least one element.
The last element of a vector is the head of the reverse vector.
Construct a Vector β (n + 1) from a Vector α n by scanning f : β → α → β
from the "left", that is, from 0 to Fin.last n, using b : β as the starting value.
Equations
- Mathlib.Vector.scanl f b v = ⟨List.scanl f b v.toList, ⋯⟩
Instances For
Providing an empty vector to scanl gives the starting value b : β.
The recursive step of scanl splits a vector x ::ᵥ v : Vector α (n + 1)
into the provided starting value b : β and the recursed scanl
f b x : β as the starting value.
This lemma is the cons version of scanl_get.
The underlying List of a Vector after a scanl is the List.scanl
of the underlying List of the original Vector.
The toList of a Vector after a scanl is the List.scanl
of the toList of the original Vector.
The recursive step of scanl splits a vector made up of a single element
x ::ᵥ nil : Vector α 1 into a Vector of the provided starting value b : β
and the mapped f b x : β as the last value.
The first element of scanl of a vector v : Vector α n,
retrieved via head, is the starting value b : β.
For an index i : Fin n, the nth element of scanl of a
vector v : Vector α n at i.succ, is equal to the application
function f : β → α → β of the castSucc i element of
scanl f b v and get v i.
This lemma is the get version of scanl_cons.
Monadic analog of Vector.ofFn.
Given a monadic function on Fin n, return a Vector α n inside the monad.
Equations
- Mathlib.Vector.mOfFn x_2 = pure Mathlib.Vector.nil
- Mathlib.Vector.mOfFn f = do let a ← f 0 let v ← Mathlib.Vector.mOfFn fun (i : Fin n) => f i.succ pure (a ::ᵥ v)
Instances For
Apply a monadic function to each component of a vector, returning a vector inside the monad.
Equations
- Mathlib.Vector.mmap f x_2 = pure Mathlib.Vector.nil
- Mathlib.Vector.mmap f xs = do let h' ← f xs.head let t' ← Mathlib.Vector.mmap f xs.tail pure (h' ::ᵥ t')
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Define C v by induction on v : Vector α n.
This function has two arguments: nil handles the base case on C nil,
and cons defines the inductive step using ∀ x : α, C w → C (x ::ᵥ w).
It is used as the default induction principle for the induction tactic.
Equations
- One or more equations did not get rendered due to their size.
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Define C v w by induction on a pair of vectors v : Vector α n and w : Vector β n.
Equations
- One or more equations did not get rendered due to their size.
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Define C u v w by induction on a triplet of vectors
u : Vector α n, v : Vector β n, and w : Vector γ b.
Equations
- One or more equations did not get rendered due to their size.
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Define motive v by case-analysis on v : Vector α n.
Equations
- Mathlib.Vector.casesOn v nil cons = v.inductionOn nil fun (x : ℕ) (hd : α) (tl : Mathlib.Vector α x) (x_1 : motive tl) => cons hd tl
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Define motive v₁ v₂ by case-analysis on v₁ : Vector α n and v₂ : Vector β n.
Equations
- Mathlib.Vector.casesOn₂ v₁ v₂ nil cons = v₁.inductionOn₂ v₂ nil fun (x : ℕ) (x_1 : α) (y : β) (xs : Mathlib.Vector α x) (ys : Mathlib.Vector β x) (x_2 : motive xs ys) => cons x_1 y xs ys
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Define motive v₁ v₂ v₃ by case-analysis on v₁ : Vector α n, v₂ : Vector β n, and
v₃ : Vector γ n.
Equations
- One or more equations did not get rendered due to their size.
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Cast a vector to an array.
Equations
- x.toArray = match x with | ⟨xs, property⟩ => cast ⋯ (List.toArray xs)
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v.insertNth a i inserts a into the vector v at position i
(and shifting later components to the right).
Equations
- Mathlib.Vector.insertNth a i v = ⟨List.insertNth (↑i) a ↑v, ⋯⟩
Instances For
Alias of Mathlib.Vector.eraseIdx_val.
Alias of Mathlib.Vector.eraseIdx_insertNth.
Alias of Mathlib.Vector.eraseIdx_insertNth'.
set v n a replaces the nth element of v with a.
Equations
- v.set i a = ⟨(↑v).set (↑i) a, ⋯⟩
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Apply an applicative function to each component of a vector.
Equations
- Mathlib.Vector.traverse f x = match x with | ⟨v, Hv⟩ => cast ⋯ (Mathlib.Vector.traverseAux f v)
Instances For
Equations
- Mathlib.Vector.instTraversableFlipNat = Traversable.mk (@Mathlib.Vector.traverse n)
Equations
- ⋯ = ⋯