List Permutations

This file introduces the List.Perm relation, which is true if two lists are permutations of one another.

Notation

The notation ~ is used for permutation equivalence.

@[simp]

theorem List.nil_subperm {α : Type u_1} {l : List α} : [].Subperm l

theorem List.Perm.subperm_left {α : Type u_1} {l : List α} {l₁ : List α} {l₂ : List α} (p : l₁.Perm l₂) : l.Subperm l₁ ↔ l.Subperm l₂

theorem List.Perm.subperm_right {α : Type u_1} {l₁ : List α} {l₂ : List α} {l : List α} (p : l₁.Perm l₂) : l₁.Subperm l ↔ l₂.Subperm l

theorem List.Sublist.subperm {α : Type u_1} {l₁ : List α} {l₂ : List α} (s : l₁.Sublist l₂) : l₁.Subperm l₂

theorem List.Perm.subperm {α : Type u_1} {l₁ : List α} {l₂ : List α} (p : l₁.Perm l₂) : l₁.Subperm l₂

theorem List.Subperm.refl {α : Type u_1} (l : List α) : l.Subperm l

theorem List.Subperm.trans {α : Type u_1} {l₁ : List α} {l₂ : List α} {l₃ : List α} (s₁₂ : l₁.Subperm l₂) (s₂₃ : l₂.Subperm l₃) : l₁.Subperm l₃

theorem List.Subperm.cons_self : ∀ {α : Type u_1} {l : List α} {a : α}, l.Subperm (a :: l)

theorem List.Subperm.cons_right {α : Type u_1} {l : List α} {l' : List α} (x : α) (h : l.Subperm l') : l.Subperm (x :: l')

theorem List.Subperm.length_le {α : Type u_1} {l₁ : List α} {l₂ : List α} : l₁.Subperm l₂ → l₁.length ≤ l₂.length

theorem List.Subperm.perm_of_length_le {α : Type u_1} {l₁ : List α} {l₂ : List α} : l₁.Subperm l₂ → l₂.length ≤ l₁.length → l₁.Perm l₂

theorem List.Subperm.antisymm {α : Type u_1} {l₁ : List α} {l₂ : List α} (h₁ : l₁.Subperm l₂) (h₂ : l₂.Subperm l₁) : l₁.Perm l₂

theorem List.Subperm.subset {α : Type u_1} {l₁ : List α} {l₂ : List α} : l₁.Subperm l₂ → l₁ ⊆ l₂

theorem List.Subperm.filter {α : Type u_1} (p : α → Bool) ⦃l : List α⦄ ⦃l' : List α⦄ (h : l.Subperm l') : (List.filter p l).Subperm (List.filter p l')

@[simp]

theorem List.subperm_nil : ∀ {α : Type u_1} {l : List α}, l.Subperm [] ↔ l = []

@[simp]

theorem List.singleton_subperm_iff {α : Type u_1} {l : List α} {a : α} : [a].Subperm l ↔ a ∈ l

theorem List.Subperm.countP_le {α : Type u_1} (p : α → Bool) {l₁ : List α} {l₂ : List α} : l₁.Subperm l₂ → List.countP p l₁ ≤ List.countP p l₂

theorem List.Subperm.count_le {α : Type u_1} [DecidableEq α] {l₁ : List α} {l₂ : List α} (s : l₁.Subperm l₂) (a : α) : List.count a l₁ ≤ List.count a l₂

theorem List.subperm_cons {α : Type u_1} (a : α) {l₁ : List α} {l₂ : List α} : (a :: l₁).Subperm (a :: l₂) ↔ l₁.Subperm l₂

theorem List.cons_subperm_of_not_mem_of_mem {α : Type u_1} {a : α} {l₁ : List α} {l₂ : List α} (h₁ : ¬a ∈ l₁) (h₂ : a ∈ l₂) (s : l₁.Subperm l₂) : (a :: l₁).Subperm l₂

Weaker version of Subperm.cons_left

theorem List.subperm_append_left {α : Type u_1} {l₁ : List α} {l₂ : List α} (l : List α) : (l ++ l₁).Subperm (l ++ l₂) ↔ l₁.Subperm l₂

theorem List.subperm_append_right {α : Type u_1} {l₁ : List α} {l₂ : List α} (l : List α) : (l₁ ++ l).Subperm (l₂ ++ l) ↔ l₁.Subperm l₂

theorem List.Subperm.exists_of_length_lt {α : Type u_1} {l₁ : List α} {l₂ : List α} (s : l₁.Subperm l₂) (h : l₁.length < l₂.length) : ∃ (a : α), (a :: l₁).Subperm l₂

theorem List.subperm_of_subset : ∀ {α : Type u_1} {l₁ l₂ : List α}, l₁.Nodup → l₁ ⊆ l₂ → l₁.Subperm l₂

theorem List.perm_ext_iff_of_nodup {α : Type u_1} {l₁ : List α} {l₂ : List α} (d₁ : l₁.Nodup) (d₂ : l₂.Nodup) : l₁.Perm l₂ ↔ ∀ (a : α), a ∈ l₁ ↔ a ∈ l₂

theorem List.Nodup.perm_iff_eq_of_sublist {α : Type u_1} {l₁ : List α} {l₂ : List α} {l : List α} (d : l.Nodup) (s₁ : l₁.Sublist l) (s₂ : l₂.Sublist l) : l₁.Perm l₂ ↔ l₁ = l₂

theorem List.subperm_cons_erase {α : Type u_1} [DecidableEq α] (a : α) (l : List α) : l.Subperm (a :: l.erase a)

theorem List.erase_subperm {α : Type u_1} [DecidableEq α] (a : α) (l : List α) : (l.erase a).Subperm l

theorem List.Subperm.erase {α : Type u_1} [DecidableEq α] {l₁ : List α} {l₂ : List α} (a : α) (h : l₁.Subperm l₂) : (l₁.erase a).Subperm (l₂.erase a)

theorem List.Perm.diff_right {α : Type u_1} [DecidableEq α] {l₁ : List α} {l₂ : List α} (t : List α) (h : l₁.Perm l₂) : (l₁.diff t).Perm (l₂.diff t)

theorem List.Perm.diff_left {α : Type u_1} [DecidableEq α] (l : List α) {t₁ : List α} {t₂ : List α} (h : t₁.Perm t₂) : l.diff t₁ = l.diff t₂

theorem List.Perm.diff {α : Type u_1} [DecidableEq α] {l₁ : List α} {l₂ : List α} {t₁ : List α} {t₂ : List α} (hl : l₁.Perm l₂) (ht : t₁.Perm t₂) : (l₁.diff t₁).Perm (l₂.diff t₂)

theorem List.Subperm.diff_right {α : Type u_1} [DecidableEq α] {l₁ : List α} {l₂ : List α} (h : l₁.Subperm l₂) (t : List α) : (l₁.diff t).Subperm (l₂.diff t)

theorem List.erase_cons_subperm_cons_erase {α : Type u_1} [DecidableEq α] (a : α) (b : α) (l : List α) : ((a :: l).erase b).Subperm (a :: l.erase b)

theorem List.subperm_cons_diff {α : Type u_1} [DecidableEq α] {a : α} {l₁ : List α} {l₂ : List α} : ((a :: l₁).diff l₂).Subperm (a :: l₁.diff l₂)

theorem List.subset_cons_diff {α : Type u_1} [DecidableEq α] {a : α} {l₁ : List α} {l₂ : List α} : (a :: l₁).diff l₂ ⊆ a :: l₁.diff l₂

theorem List.subperm_append_diff_self_of_count_le {α : Type u_1} [DecidableEq α] {l₁ : List α} {l₂ : List α} (h : ∀ (x : α), x ∈ l₁ → List.count x l₁ ≤ List.count x l₂) : (l₁ ++ l₂.diff l₁).Perm l₂

The list version of add_tsub_cancel_of_le for multisets.

theorem List.subperm_ext_iff {α : Type u_1} [DecidableEq α] {l₁ : List α} {l₂ : List α} : l₁.Subperm l₂ ↔ ∀ (x : α), x ∈ l₁ → List.count x l₁ ≤ List.count x l₂

The list version of Multiset.le_iff_count.

theorem List.isSubperm_iff {α : Type u_1} [DecidableEq α] {l₁ : List α} {l₂ : List α} : l₁.isSubperm l₂ = true ↔ l₁.Subperm l₂

instance List.decidableSubperm {α : Type u_1} [DecidableEq α] : DecidableRel fun (x1 x2 : List α) => x1.Subperm x2

Equations

• x✝.decidableSubperm x = decidable_of_iff (x✝.isSubperm x = true) ⋯

theorem List.Subperm.cons_left {α : Type u_1} [DecidableEq α] {l₁ : List α} {l₂ : List α} (h : l₁.Subperm l₂) (x : α) (hx : List.count x l₁ < List.count x l₂) : (x :: l₁).Subperm l₂

theorem List.perm_insertIdx {α : Type u_1} (x : α) (l : List α) {n : Nat} (h : n ≤ l.length) : (List.insertIdx n x l).Perm (x :: l)

@[deprecated List.perm_insertIdx]

theorem List.perm_insertNth {α : Type u_1} (x : α) (l : List α) {n : Nat} (h : n ≤ l.length) : (List.insertIdx n x l).Perm (x :: l)

Alias of List.perm_insertIdx.

theorem List.Perm.union_right {α : Type u_1} [DecidableEq α] {l₁ : List α} {l₂ : List α} (t₁ : List α) (h : l₁.Perm l₂) : (l₁ ∪ t₁).Perm (l₂ ∪ t₁)

theorem List.Perm.union_left {α : Type u_1} [DecidableEq α] (l : List α) {t₁ : List α} {t₂ : List α} (h : t₁.Perm t₂) : (l ∪ t₁).Perm (l ∪ t₂)

theorem List.Perm.union {α : Type u_1} [DecidableEq α] {l₁ : List α} {l₂ : List α} {t₁ : List α} {t₂ : List α} (p₁ : l₁.Perm l₂) (p₂ : t₁.Perm t₂) : (l₁ ∪ t₁).Perm (l₂ ∪ t₂)

theorem List.Perm.inter_right {α : Type u_1} [DecidableEq α] {l₁ : List α} {l₂ : List α} (t₁ : List α) : l₁.Perm l₂ → (l₁ ∩ t₁).Perm (l₂ ∩ t₁)

theorem List.Perm.inter_left {α : Type u_1} [DecidableEq α] (l : List α) {t₁ : List α} {t₂ : List α} (p : t₁.Perm t₂) : l ∩ t₁ = l ∩ t₂

theorem List.Perm.inter {α : Type u_1} [DecidableEq α] {l₁ : List α} {l₂ : List α} {t₁ : List α} {t₂ : List α} (p₁ : l₁.Perm l₂) (p₂ : t₁.Perm t₂) : (l₁ ∩ t₁).Perm (l₂ ∩ t₂)

theorem List.Perm.join_congr {α : Type u_1} {l₁ : List (List α)} {l₂ : List (List α)} : List.Forall₂ (fun (x1 x2 : List α) => x1.Perm x2) l₁ l₂ → l₁.join.Perm l₂.join

theorem List.perm_insertP {α : Type u_1} (p : α → Bool) (a : α) (l : List α) : (List.insertP p a l).Perm (a :: l)

theorem List.Perm.insertP {α : Type u_1} {l₁ : List α} {l₂ : List α} (p : α → Bool) (a : α) (h : l₁.Perm l₂) : (List.insertP p a l₁).Perm (List.insertP p a l₂)

@[irreducible]

theorem List.perm_merge {α : Type u_1} (s : α → α → Bool) (l : List α) (r : List α) : (l.merge r s).Perm (l ++ r)

theorem List.Perm.merge {α : Type u_1} {l₁ : List α} {l₂ : List α} {r₁ : List α} {r₂ : List α} (s₁ : α → α → Bool) (s₂ : α → α → Bool) (hl : l₁.Perm l₂) (hr : r₁.Perm r₂) : (l₁.merge r₁ s₁).Perm (l₂.merge r₂ s₂)