Documentation

Batteries.Data.List.Lemmas

toArray #

@[simp]
theorem List.getElem_mk {α : Type u_1} {xs : List α} {i : Nat} (h : i < xs.length) :
{ toList := xs }[i] = xs[i]

isEmpty #

theorem List.isEmpty_iff_eq_nil {α : Type u_1} {l : List α} :
l.isEmpty = true l = []

next? #

@[simp]
theorem List.next?_nil {α : Type u_1} :
[].next? = none
@[simp]
theorem List.next?_cons {α : Type u_1} (a : α) (l : List α) :
(a :: l).next? = some (a, l)

dropLast #

theorem List.dropLast_eq_eraseIdx {α : Type u_1} {xs : List α} {i : Nat} (last_idx : i + 1 = xs.length) :
xs.dropLast = xs.eraseIdx i

get? #

@[deprecated List.getElem_eq_iff]
theorem List.get_eq_iff :
∀ {α : Type u_1} {l : List α} {n : Fin l.length} {x : α}, l.get n = x l.get? n = some x
@[deprecated List.getElem?_inj]
theorem List.get?_inj {i : Nat} :
∀ {α : Type u_1} {xs : List α} {j : Nat}, i < xs.lengthxs.Nodupxs.get? i = xs.get? ji = j

modifyHead #

@[simp]
theorem List.modifyHead_modifyHead {α : Type u_1} (l : List α) (f : αα) (g : αα) :

modifyNth #

@[simp]
theorem List.modifyNth_nil {α : Type u_1} (f : αα) (n : Nat) :
List.modifyNth f n [] = []
@[simp]
theorem List.modifyNth_zero_cons {α : Type u_1} (f : αα) (a : α) (l : List α) :
List.modifyNth f 0 (a :: l) = f a :: l
@[simp]
theorem List.modifyNth_succ_cons {α : Type u_1} (f : αα) (a : α) (l : List α) (n : Nat) :
List.modifyNth f (n + 1) (a :: l) = a :: List.modifyNth f n l
theorem List.modifyNthTail_id {α : Type u_1} (n : Nat) (l : List α) :
theorem List.eraseIdx_eq_modifyNthTail {α : Type u_1} (n : Nat) (l : List α) :
l.eraseIdx n = List.modifyNthTail List.tail n l
@[deprecated List.eraseIdx_eq_modifyNthTail]
theorem List.removeNth_eq_nth_tail {α : Type u_1} (n : Nat) (l : List α) :
l.eraseIdx n = List.modifyNthTail List.tail n l

Alias of List.eraseIdx_eq_modifyNthTail.

theorem List.getElem?_modifyNth {α : Type u_1} (f : αα) (n : Nat) (l : List α) (m : Nat) :
(List.modifyNth f n l)[m]? = (fun (a : α) => if n = m then f a else a) <$> l[m]?
@[deprecated List.getElem?_modifyNth]
theorem List.get?_modifyNth {α : Type u_1} (f : αα) (n : Nat) (l : List α) (m : Nat) :
(List.modifyNth f n l).get? m = (fun (a : α) => if n = m then f a else a) <$> l.get? m
theorem List.length_modifyNthTail {α : Type u_1} (f : List αList α) (H : ∀ (l : List α), (f l).length = l.length) (n : Nat) (l : List α) :
(List.modifyNthTail f n l).length = l.length
@[deprecated List.length_modifyNthTail]
theorem List.modifyNthTail_length {α : Type u_1} (f : List αList α) (H : ∀ (l : List α), (f l).length = l.length) (n : Nat) (l : List α) :
(List.modifyNthTail f n l).length = l.length

Alias of List.length_modifyNthTail.

theorem List.modifyNthTail_add {α : Type u_1} (f : List αList α) (n : Nat) (l₁ : List α) (l₂ : List α) :
List.modifyNthTail f (l₁.length + n) (l₁ ++ l₂) = l₁ ++ List.modifyNthTail f n l₂
theorem List.exists_of_modifyNthTail {α : Type u_1} (f : List αList α) {n : Nat} {l : List α} (h : n l.length) :
∃ (l₁ : List α), ∃ (l₂ : List α), l = l₁ ++ l₂ l₁.length = n List.modifyNthTail f n l = l₁ ++ f l₂
@[simp]
theorem List.length_modifyNth {α : Type u_1} (f : αα) (n : Nat) (l : List α) :
(List.modifyNth f n l).length = l.length
@[deprecated List.length_modifyNth]
theorem List.modify_get?_length {α : Type u_1} (f : αα) (n : Nat) (l : List α) :
(List.modifyNth f n l).length = l.length

Alias of List.length_modifyNth.

@[simp]
theorem List.getElem?_modifyNth_eq {α : Type u_1} (f : αα) (n : Nat) (l : List α) :
(List.modifyNth f n l)[n]? = f <$> l[n]?
@[deprecated List.getElem?_modifyNth_eq]
theorem List.get?_modifyNth_eq {α : Type u_1} (f : αα) (n : Nat) (l : List α) :
(List.modifyNth f n l).get? n = f <$> l.get? n
@[simp]
theorem List.getElem?_modifyNth_ne {α : Type u_1} (f : αα) {m : Nat} {n : Nat} (l : List α) (h : m n) :
(List.modifyNth f m l)[n]? = l[n]?
@[deprecated List.getElem?_modifyNth_ne]
theorem List.get?_modifyNth_ne {α : Type u_1} (f : αα) {m : Nat} {n : Nat} (l : List α) (h : m n) :
(List.modifyNth f m l).get? n = l.get? n
theorem List.exists_of_modifyNth {α : Type u_1} (f : αα) {n : Nat} {l : List α} (h : n < l.length) :
∃ (l₁ : List α), ∃ (a : α), ∃ (l₂ : List α), l = l₁ ++ a :: l₂ l₁.length = n List.modifyNth f n l = l₁ ++ f a :: l₂
theorem List.modifyNthTail_eq_take_drop {α : Type u_1} (f : List αList α) (H : f [] = []) (n : Nat) (l : List α) :
theorem List.modifyNth_eq_take_drop {α : Type u_1} (f : αα) (n : Nat) (l : List α) :
theorem List.modifyNth_eq_take_cons_drop {α : Type u_1} (f : αα) {n : Nat} {l : List α} (h : n < l.length) :
List.modifyNth f n l = List.take n l ++ f l[n] :: List.drop (n + 1) l

set #

theorem List.set_eq_modifyNth {α : Type u_1} (a : α) (n : Nat) (l : List α) :
l.set n a = List.modifyNth (fun (x : α) => a) n l
theorem List.set_eq_take_cons_drop {α : Type u_1} (a : α) {n : Nat} {l : List α} (h : n < l.length) :
l.set n a = List.take n l ++ a :: List.drop (n + 1) l
theorem List.modifyNth_eq_set_get? {α : Type u_1} (f : αα) (n : Nat) (l : List α) :
List.modifyNth f n l = ((fun (a : α) => l.set n (f a)) <$> l.get? n).getD l
theorem List.modifyNth_eq_set_get {α : Type u_1} (f : αα) {n : Nat} {l : List α} (h : n < l.length) :
List.modifyNth f n l = l.set n (f (l.get n, h))
@[deprecated List.exists_of_set]
theorem List.exists_of_set' {α : Type u_1} {n : Nat} {a' : α} {l : List α} (h : n < l.length) :
∃ (l₁ : List α), ∃ (a : α), ∃ (l₂ : List α), l = l₁ ++ a :: l₂ l₁.length = n l.set n a' = l₁ ++ a' :: l₂
@[deprecated List.getElem?_set_self']
theorem List.get?_set_eq {α : Type u_1} (a : α) (n : Nat) (l : List α) :
(l.set n a).get? n = (fun (x : α) => a) <$> l.get? n
theorem List.getElem?_set_eq_of_lt {α : Type u_1} (a : α) {n : Nat} {l : List α} (h : n < l.length) :
(l.set n a)[n]? = some a
@[deprecated List.getElem?_set_eq_of_lt]
theorem List.get?_set_eq_of_lt {α : Type u_1} (a : α) {n : Nat} {l : List α} (h : n < l.length) :
(l.set n a).get? n = some a
@[deprecated List.getElem?_set_ne]
theorem List.get?_set_ne {α : Type u_1} (a : α) {m : Nat} {n : Nat} (l : List α) (h : m n) :
(l.set m a).get? n = l.get? n
@[deprecated List.getElem?_set]
theorem List.get?_set {α : Type u_1} (a : α) {m : Nat} {n : Nat} (l : List α) :
(l.set m a).get? n = if m = n then (fun (x : α) => a) <$> l.get? n else l.get? n
theorem List.get?_set_of_lt {α : Type u_1} (a : α) {m : Nat} {n : Nat} (l : List α) (h : n < l.length) :
(l.set m a).get? n = if m = n then some a else l.get? n
theorem List.get?_set_of_lt' {α : Type u_1} (a : α) {m : Nat} {n : Nat} (l : List α) (h : m < l.length) :
(l.set m a).get? n = if m = n then some a else l.get? n
@[deprecated List.length_eraseIdx]
theorem List.length_removeNth {α : Type u_1} (l : List α) (i : Nat) :
(l.eraseIdx i).length = if i < l.length then l.length - 1 else l.length

Alias of List.length_eraseIdx.

tail #

theorem List.length_tail_add_one {α : Type u_1} (l : List α) (h : 0 < l.length) :
l.tail.length + 1 = l.length

eraseP #

@[simp]
theorem List.extractP_eq_find?_eraseP {α : Type u_1} {p : αBool} (l : List α) :
theorem List.extractP_eq_find?_eraseP.go {α : Type u_1} {p : αBool} (l : List α) (acc : Array α) (xs : List α) :
l = acc.toList ++ xsList.extractP.go p l xs acc = (List.find? p xs, acc.toList ++ List.eraseP p xs)

erase #

@[deprecated List.Sublist.erase]
theorem List.sublist.erase {α : Type u_1} [BEq α] (a : α) {l₁ : List α} {l₂ : List α} (h : l₁.Sublist l₂) :
(l₁.erase a).Sublist (l₂.erase a)

Alias of List.Sublist.erase.

theorem List.erase_eq_self_iff_forall_bne {α : Type u_1} [BEq α] (a : α) (xs : List α) :
xs.erase a = xs ∀ (x : α), x xs¬(x == a) = true

findIdx? #

theorem List.findIdx_eq_findIdx? {α : Type u_1} (p : αBool) (l : List α) :
List.findIdx p l = match List.findIdx? p l with | some i => i | none => l.length

replaceF #

theorem List.replaceF_nil :
∀ {α : Type u_1} {p : αOption α}, List.replaceF p [] = []
theorem List.replaceF_cons {α : Type u_1} {p : αOption α} (a : α) (l : List α) :
List.replaceF p (a :: l) = match p a with | none => a :: List.replaceF p l | some a' => a' :: l
theorem List.replaceF_cons_of_some {α : Type u_1} {a' : α} {a : α} {l : List α} (p : αOption α) (h : p a = some a') :
List.replaceF p (a :: l) = a' :: l
theorem List.replaceF_cons_of_none {α : Type u_1} {a : α} {l : List α} (p : αOption α) (h : p a = none) :
theorem List.replaceF_of_forall_none {α : Type u_1} {p : αOption α} {l : List α} (h : ∀ (a : α), a lp a = none) :
theorem List.exists_of_replaceF {α : Type u_1} {p : αOption α} {l : List α} {a : α} {a' : α} :
a lp a = some a'∃ (a : α), ∃ (a' : α), ∃ (l₁ : List α), ∃ (l₂ : List α), (∀ (b : α), b l₁p b = none) p a = some a' l = l₁ ++ a :: l₂ List.replaceF p l = l₁ ++ a' :: l₂
theorem List.exists_or_eq_self_of_replaceF {α : Type u_1} (p : αOption α) (l : List α) :
List.replaceF p l = l ∃ (a : α), ∃ (a' : α), ∃ (l₁ : List α), ∃ (l₂ : List α), (∀ (b : α), b l₁p b = none) p a = some a' l = l₁ ++ a :: l₂ List.replaceF p l = l₁ ++ a' :: l₂
@[simp]
theorem List.length_replaceF :
∀ {α : Type u_1} {f : αOption α} {l : List α}, (List.replaceF f l).length = l.length

disjoint #

theorem List.disjoint_symm :
∀ {α : Type u_1} {l₁ l₂ : List α}, l₁.Disjoint l₂l₂.Disjoint l₁
theorem List.disjoint_comm :
∀ {α : Type u_1} {l₁ l₂ : List α}, l₁.Disjoint l₂ l₂.Disjoint l₁
theorem List.disjoint_left :
∀ {α : Type u_1} {l₁ l₂ : List α}, l₁.Disjoint l₂ ∀ ⦃a : α⦄, a l₁¬a l₂
theorem List.disjoint_right :
∀ {α : Type u_1} {l₁ l₂ : List α}, l₁.Disjoint l₂ ∀ ⦃a : α⦄, a l₂¬a l₁
theorem List.disjoint_iff_ne :
∀ {α : Type u_1} {l₁ l₂ : List α}, l₁.Disjoint l₂ ∀ (a : α), a l₁∀ (b : α), b l₂a b
theorem List.disjoint_of_subset_left :
∀ {α : Type u_1} {l₁ l l₂ : List α}, l₁ ll.Disjoint l₂l₁.Disjoint l₂
theorem List.disjoint_of_subset_right :
∀ {α : Type u_1} {l₂ l l₁ : List α}, l₂ ll₁.Disjoint ll₁.Disjoint l₂
theorem List.disjoint_of_disjoint_cons_left :
∀ {α : Type u_1} {a : α} {l₁ l₂ : List α}, (a :: l₁).Disjoint l₂l₁.Disjoint l₂
theorem List.disjoint_of_disjoint_cons_right :
∀ {α : Type u_1} {a : α} {l₁ l₂ : List α}, l₁.Disjoint (a :: l₂)l₁.Disjoint l₂
@[simp]
theorem List.disjoint_nil_left {α : Type u_1} (l : List α) :
[].Disjoint l
@[simp]
theorem List.disjoint_nil_right {α : Type u_1} (l : List α) :
l.Disjoint []
@[simp]
theorem List.singleton_disjoint :
∀ {α : Type u_1} {a : α} {l : List α}, [a].Disjoint l ¬a l
@[simp]
theorem List.disjoint_singleton :
∀ {α : Type u_1} {l : List α} {a : α}, l.Disjoint [a] ¬a l
@[simp]
theorem List.disjoint_append_left :
∀ {α : Type u_1} {l₁ l₂ l : List α}, (l₁ ++ l₂).Disjoint l l₁.Disjoint l l₂.Disjoint l
@[simp]
theorem List.disjoint_append_right :
∀ {α : Type u_1} {l l₁ l₂ : List α}, l.Disjoint (l₁ ++ l₂) l.Disjoint l₁ l.Disjoint l₂
@[simp]
theorem List.disjoint_cons_left :
∀ {α : Type u_1} {a : α} {l₁ l₂ : List α}, (a :: l₁).Disjoint l₂ ¬a l₂ l₁.Disjoint l₂
@[simp]
theorem List.disjoint_cons_right :
∀ {α : Type u_1} {l₁ : List α} {a : α} {l₂ : List α}, l₁.Disjoint (a :: l₂) ¬a l₁ l₁.Disjoint l₂
theorem List.disjoint_of_disjoint_append_left_left :
∀ {α : Type u_1} {l₁ l₂ l : List α}, (l₁ ++ l₂).Disjoint ll₁.Disjoint l
theorem List.disjoint_of_disjoint_append_left_right :
∀ {α : Type u_1} {l₁ l₂ l : List α}, (l₁ ++ l₂).Disjoint ll₂.Disjoint l
theorem List.disjoint_of_disjoint_append_right_left :
∀ {α : Type u_1} {l l₁ l₂ : List α}, l.Disjoint (l₁ ++ l₂)l.Disjoint l₁
theorem List.disjoint_of_disjoint_append_right_right :
∀ {α : Type u_1} {l l₁ l₂ : List α}, l.Disjoint (l₁ ++ l₂)l.Disjoint l₂

union #

theorem List.union_def {α : Type u_1} [BEq α] (l₁ : List α) (l₂ : List α) :
l₁ l₂ = List.foldr List.insert l₂ l₁
@[simp]
theorem List.nil_union {α : Type u_1} [BEq α] (l : List α) :
[] l = l
@[simp]
theorem List.cons_union {α : Type u_1} [BEq α] (a : α) (l₁ : List α) (l₂ : List α) :
a :: l₁ l₂ = List.insert a (l₁ l₂)
@[simp]
theorem List.mem_union_iff {α : Type u_1} [BEq α] [LawfulBEq α] {x : α} {l₁ : List α} {l₂ : List α} :
x l₁ l₂ x l₁ x l₂

inter #

theorem List.inter_def {α : Type u_1} [BEq α] (l₁ : List α) (l₂ : List α) :
l₁ l₂ = List.filter (fun (x : α) => List.elem x l₂) l₁
@[simp]
theorem List.mem_inter_iff {α : Type u_1} [BEq α] [LawfulBEq α] {x : α} {l₁ : List α} {l₂ : List α} :
x l₁ l₂ x l₁ x l₂

product #

@[simp]
theorem List.pair_mem_product {α : Type u_1} {β : Type u_2} {xs : List α} {ys : List β} {x : α} {y : β} :
(x, y) xs.product ys x xs y ys

List.prod satisfies a specification of cartesian product on lists.

monadic operations #

theorem List.forIn_eq_bindList {m : Type u_1 → Type u_2} {α : Type u_3} {β : Type u_1} [Monad m] [LawfulMonad m] (f : αβm (ForInStep β)) (l : List α) (init : β) :
forIn l init f = ForInStep.run <$> ForInStep.bindList f l (ForInStep.yield init)

diff #

@[simp]
theorem List.diff_nil {α : Type u_1} [BEq α] (l : List α) :
l.diff [] = l
@[simp]
theorem List.diff_cons {α : Type u_1} [BEq α] [LawfulBEq α] (l₁ : List α) (l₂ : List α) (a : α) :
l₁.diff (a :: l₂) = (l₁.erase a).diff l₂
theorem List.diff_cons_right {α : Type u_1} [BEq α] [LawfulBEq α] (l₁ : List α) (l₂ : List α) (a : α) :
l₁.diff (a :: l₂) = (l₁.diff l₂).erase a
theorem List.diff_erase {α : Type u_1} [BEq α] [LawfulBEq α] (l₁ : List α) (l₂ : List α) (a : α) :
(l₁.diff l₂).erase a = (l₁.erase a).diff l₂
@[simp]
theorem List.nil_diff {α : Type u_1} [BEq α] [LawfulBEq α] (l : List α) :
[].diff l = []
theorem List.cons_diff {α : Type u_1} [BEq α] [LawfulBEq α] (a : α) (l₁ : List α) (l₂ : List α) :
(a :: l₁).diff l₂ = if a l₂ then l₁.diff (l₂.erase a) else a :: l₁.diff l₂
theorem List.cons_diff_of_mem {α : Type u_1} [BEq α] [LawfulBEq α] {a : α} {l₂ : List α} (h : a l₂) (l₁ : List α) :
(a :: l₁).diff l₂ = l₁.diff (l₂.erase a)
theorem List.cons_diff_of_not_mem {α : Type u_1} [BEq α] [LawfulBEq α] {a : α} {l₂ : List α} (h : ¬a l₂) (l₁ : List α) :
(a :: l₁).diff l₂ = a :: l₁.diff l₂
theorem List.diff_eq_foldl {α : Type u_1} [BEq α] [LawfulBEq α] (l₁ : List α) (l₂ : List α) :
l₁.diff l₂ = List.foldl List.erase l₁ l₂
@[simp]
theorem List.diff_append {α : Type u_1} [BEq α] [LawfulBEq α] (l₁ : List α) (l₂ : List α) (l₃ : List α) :
l₁.diff (l₂ ++ l₃) = (l₁.diff l₂).diff l₃
theorem List.diff_sublist {α : Type u_1} [BEq α] [LawfulBEq α] (l₁ : List α) (l₂ : List α) :
(l₁.diff l₂).Sublist l₁
theorem List.diff_subset {α : Type u_1} [BEq α] [LawfulBEq α] (l₁ : List α) (l₂ : List α) :
l₁.diff l₂ l₁
theorem List.mem_diff_of_mem {α : Type u_1} [BEq α] [LawfulBEq α] {a : α} {l₁ : List α} {l₂ : List α} :
a l₁¬a l₂a l₁.diff l₂
theorem List.Sublist.diff_right {α : Type u_1} [BEq α] [LawfulBEq α] {l₁ : List α} {l₂ : List α} {l₃ : List α} :
l₁.Sublist l₂(l₁.diff l₃).Sublist (l₂.diff l₃)
theorem List.Sublist.erase_diff_erase_sublist {α : Type u_1} [BEq α] [LawfulBEq α] {a : α} {l₁ : List α} {l₂ : List α} :
l₁.Sublist l₂((l₂.erase a).diff (l₁.erase a)).Sublist (l₂.diff l₁)

drop #

theorem List.disjoint_take_drop {α : Type u_1} {m : Nat} {n : Nat} {l : List α} :
l.Nodupm n(List.take m l).Disjoint (List.drop n l)

Chain #

@[simp]
theorem List.chain_cons {α : Type u_1} {R : ααProp} {a : α} {b : α} {l : List α} :
List.Chain R a (b :: l) R a b List.Chain R b l
theorem List.rel_of_chain_cons {α : Type u_1} {R : ααProp} {a : α} {b : α} {l : List α} (p : List.Chain R a (b :: l)) :
R a b
theorem List.chain_of_chain_cons {α : Type u_1} {R : ααProp} {a : α} {b : α} {l : List α} (p : List.Chain R a (b :: l)) :
theorem List.Chain.imp' {α : Type u_1} {R : ααProp} {S : ααProp} (HRS : ∀ ⦃a b : α⦄, R a bS a b) {a : α} {b : α} (Hab : ∀ ⦃c : α⦄, R a cS b c) {l : List α} (p : List.Chain R a l) :
theorem List.Chain.imp {α : Type u_1} {R : ααProp} {S : ααProp} (H : ∀ (a b : α), R a bS a b) {a : α} {l : List α} (p : List.Chain R a l) :
theorem List.Pairwise.chain :
∀ {α : Type u_1} {R : ααProp} {a : α} {l : List α}, List.Pairwise R (a :: l)List.Chain R a l

range', range #

theorem List.chain_succ_range' (s : Nat) (n : Nat) (step : Nat) :
List.Chain (fun (a b : Nat) => b = a + step) s (List.range' (s + step) n step)
theorem List.chain_lt_range' (s : Nat) (n : Nat) {step : Nat} (h : 0 < step) :
List.Chain (fun (x1 x2 : Nat) => x1 < x2) s (List.range' (s + step) n step)
@[deprecated List.getElem?_range']
theorem List.get?_range' (s : Nat) (step : Nat) {m : Nat} {n : Nat} (h : m < n) :
(List.range' s n step).get? m = some (s + step * m)
@[deprecated List.getElem_range']
theorem List.get_range' {n : Nat} {m : Nat} {step : Nat} (i : Nat) (H : i < (List.range' n m step).length) :
(List.range' n m step).get i, H = n + step * i
@[deprecated List.getElem?_range]
theorem List.get?_range {m : Nat} {n : Nat} (h : m < n) :
(List.range n).get? m = some m
@[deprecated List.getElem_range]
theorem List.get_range {n : Nat} (i : Nat) (H : i < (List.range n).length) :
(List.range n).get i, H = i

indexOf and indexesOf #

theorem List.foldrIdx_start {α : Type u_1} {xs : List α} :
∀ {α_1 : Sort u_2} {f : Natαα_1α_1} {i : α_1} {s : Nat}, List.foldrIdx f i xs s = List.foldrIdx (fun (i : Nat) => f (i + s)) i xs
@[simp]
theorem List.foldrIdx_cons {α : Type u_1} {x : α} {xs : List α} :
∀ {α_1 : Sort u_2} {f : Natαα_1α_1} {i : α_1} {s : Nat}, List.foldrIdx f i (x :: xs) s = f s x (List.foldrIdx f i xs (s + 1))
theorem List.findIdxs_cons_aux {α : Type u_1} {xs : List α} {s : Nat} (p : αBool) :
List.foldrIdx (fun (i : Nat) (a : α) (is : List Nat) => if p a = true then (i + 1) :: is else is) [] xs s = List.map (fun (x : Nat) => x + 1) (List.foldrIdx (fun (i : Nat) (a : α) (is : List Nat) => if p a = true then i :: is else is) [] xs s)
theorem List.findIdxs_cons {α : Type u_1} {x : α} {xs : List α} {p : αBool} :
List.findIdxs p (x :: xs) = bif p x then 0 :: List.map (fun (x : Nat) => x + 1) (List.findIdxs p xs) else List.map (fun (x : Nat) => x + 1) (List.findIdxs p xs)
@[simp]
theorem List.indexesOf_nil {α : Type u_1} {x : α} [BEq α] :
theorem List.indexesOf_cons {α : Type u_1} {x : α} {xs : List α} {y : α} [BEq α] :
List.indexesOf y (x :: xs) = bif x == y then 0 :: List.map (fun (x : Nat) => x + 1) (List.indexesOf y xs) else List.map (fun (x : Nat) => x + 1) (List.indexesOf y xs)
@[simp]
theorem List.eraseIdx_indexOf_eq_erase {α : Type u_1} [BEq α] (a : α) (l : List α) :
l.eraseIdx (List.indexOf a l) = l.erase a
theorem List.indexOf_mem_indexesOf {α : Type u_1} {x : α} [BEq α] [LawfulBEq α] {xs : List α} (m : x xs) :
@[simp]
theorem List.indexOf?_nil {α : Type u_1} {x : α} [BEq α] :
List.indexOf? x [] = none
theorem List.indexOf?_cons {α : Type u_1} {x : α} {xs : List α} {y : α} [BEq α] :
List.indexOf? y (x :: xs) = if (x == y) = true then some 0 else Option.map Nat.succ (List.indexOf? y xs)
theorem List.indexOf?_eq_none_iff {α : Type u_1} [BEq α] {a : α} {l : List α} :
List.indexOf? a l = none ∀ (x : α), x l¬(x == a) = true
theorem List.indexOf_eq_indexOf? {α : Type u_1} [BEq α] (a : α) (l : List α) :
List.indexOf a l = match List.indexOf? a l with | some i => i | none => l.length

insertP #

theorem List.insertP_loop {α : Type u_1} {p : αBool} (a : α) (l : List α) (r : List α) :
List.insertP.loop p a l r = r.reverseAux (List.insertP p a l)
@[simp]
theorem List.insertP_nil {α : Type u_1} (p : αBool) (a : α) :
List.insertP p a [] = [a]
@[simp]
theorem List.insertP_cons_pos {α : Type u_1} (p : αBool) (a : α) (b : α) (l : List α) (h : p b = true) :
List.insertP p a (b :: l) = a :: b :: l
@[simp]
theorem List.insertP_cons_neg {α : Type u_1} (p : αBool) (a : α) (b : α) (l : List α) (h : ¬p b = true) :
List.insertP p a (b :: l) = b :: List.insertP p a l
@[simp]
theorem List.length_insertP {α : Type u_1} (p : αBool) (a : α) (l : List α) :
(List.insertP p a l).length = l.length + 1
@[simp]
theorem List.mem_insertP {α : Type u_1} (p : αBool) (a : α) (l : List α) :

foldlM and foldrM #

theorem List.foldlM_map {m : Type u_1 → Type u_2} {β₁ : Type u_3} {β₂ : Type u_4} {α : Type u_1} [Monad m] (f : β₁β₂) (g : αβ₂m α) (l : List β₁) (init : α) :
List.foldlM g init (List.map f l) = List.foldlM (fun (x : α) (y : β₁) => g x (f y)) init l
theorem List.foldrM_map {m : Type u_1 → Type u_2} {β₁ : Type u_3} {β₂ : Type u_4} {α : Type u_1} [Monad m] [LawfulMonad m] (f : β₁β₂) (g : β₂αm α) (l : List β₁) (init : α) :
List.foldrM g init (List.map f l) = List.foldrM (fun (x : β₁) (y : α) => g (f x) y) init l