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Author SHA1 Message Date
Kim Morrison
f172b32379 fixes 2024-10-17 14:18:07 +11:00
Kim Morrison
e4455947fb chore: cleanup in Array/Lemmas 2024-10-17 13:56:25 +11:00
11 changed files with 43 additions and 476 deletions

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@@ -1937,6 +1937,15 @@ instance : Subsingleton (Squash α) where
apply Quot.sound
trivial
/-! # Relations -/
/--
`Antisymm (·≤·)` says that `(·≤·)` is antisymmetric, that is, `a ≤ b → b ≤ a → a = b`.
-/
class Antisymm {α : Sort u} (r : α α Prop) : Prop where
/-- An antisymmetric relation `(·≤·)` satisfies `a ≤ b → b ≤ a → a = b`. -/
antisymm {a b : α} : r a b r b a a = b
namespace Lean
/-! # Kernel reduction hints -/
@@ -2112,14 +2121,4 @@ instance : Commutative Or := ⟨fun _ _ => propext or_comm⟩
instance : Commutative And := fun _ _ => propext and_comm
instance : Commutative Iff := fun _ _ => propext iff_comm
/--
`Antisymm (·≤·)` says that `(·≤·)` is antisymmetric, that is, `a ≤ b → b ≤ a → a = b`.
-/
class Antisymm (r : α α Prop) : Prop where
/-- An antisymmetric relation `(·≤·)` satisfies `a ≤ b → b ≤ a → a = b`. -/
antisymm {a b : α} : r a b r b a a = b
@[deprecated Antisymm (since := "2024-10-16"), inherit_doc Antisymm]
abbrev _root_.Antisymm (r : α α Prop) : Prop := Std.Antisymm r
end Std

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@@ -25,8 +25,6 @@ variable {α : Type u}
namespace Array
@[deprecated size (since := "2024-10-13")] abbrev data := @toList
/-! ### Preliminary theorems -/
@[simp] theorem size_set (a : Array α) (i : Fin a.size) (v : α) : (set a i v).size = a.size :=

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@@ -232,8 +232,7 @@ theorem sizeOf_get [SizeOf α] (as : List α) (i : Fin as.length) : sizeOf (as.g
apply Nat.lt_trans ih
simp_arith
theorem le_antisymm [LT α] [s : Std.Antisymm (¬ · < · : α α Prop)]
{as bs : List α} (h₁ : as bs) (h₂ : bs as) : as = bs :=
theorem le_antisymm [LT α] [s : Antisymm (¬ · < · : α α Prop)] {as bs : List α} (h₁ : as bs) (h₂ : bs as) : as = bs :=
match as, bs with
| [], [] => rfl
| [], _::_ => False.elim <| h₂ (List.lt.nil ..)
@@ -249,8 +248,7 @@ theorem le_antisymm [LT α] [s : Std.Antisymm (¬ · < · : αα → Prop)]
have : a = b := s.antisymm hab hba
simp [this, ih]
instance [LT α] [Std.Antisymm (¬ · < · : α α Prop)] :
Std.Antisymm (· · : List α List α Prop) where
instance [LT α] [Antisymm (¬ · < · : α α Prop)] : Antisymm (· · : List α List α Prop) where
antisymm h₁ h₂ := le_antisymm h₁ h₂
end List

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@@ -75,7 +75,7 @@ theorem le_min?_iff [Min α] [LE α]
-- This could be refactored by designing appropriate typeclasses to replace `le_refl`, `min_eq_or`,
-- and `le_min_iff`.
theorem min?_eq_some_iff [Min α] [LE α] [anti : Std.Antisymm ((· : α) ·)]
theorem min?_eq_some_iff [Min α] [LE α] [anti : Antisymm ((· : α) ·)]
(le_refl : a : α, a a)
(min_eq_or : a b : α, min a b = a min a b = b)
(le_min_iff : a b c : α, a min b c a b a c) {xs : List α} :
@@ -146,7 +146,7 @@ theorem max?_le_iff [Max α] [LE α]
-- This could be refactored by designing appropriate typeclasses to replace `le_refl`, `max_eq_or`,
-- and `le_min_iff`.
theorem max?_eq_some_iff [Max α] [LE α] [anti : Std.Antisymm ((· : α) ·)]
theorem max?_eq_some_iff [Max α] [LE α] [anti : Antisymm ((· : α) ·)]
(le_refl : a : α, a a)
(max_eq_or : a b : α, max a b = a max a b = b)
(max_le_iff : a b c : α, max b c a b a c a) {xs : List α} :

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@@ -490,10 +490,10 @@ protected theorem le_antisymm_iff {a b : Nat} : a = b ↔ a ≤ b ∧ b ≤ a :=
(fun hle, hge => Nat.le_antisymm hle hge)
protected theorem eq_iff_le_and_ge : {a b : Nat}, a = b a b b a := @Nat.le_antisymm_iff
instance : Std.Antisymm ( . . : Nat Nat Prop) where
instance : Antisymm ( . . : Nat Nat Prop) where
antisymm h₁ h₂ := Nat.le_antisymm h₁ h₂
instance : Std.Antisymm (¬ . < . : Nat Nat Prop) where
instance : Antisymm (¬ . < . : Nat Nat Prop) where
antisymm h₁ h₂ := Nat.le_antisymm (Nat.ge_of_not_lt h₂) (Nat.ge_of_not_lt h₁)
protected theorem add_le_add_left {n m : Nat} (h : n m) (k : Nat) : k + n k + m :=

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@@ -1148,23 +1148,23 @@ namespace String
/--
If `pre` is a prefix of `s`, i.e. `s = pre ++ t`, returns the remainder `t`.
-/
def dropPrefix? (s : String) (pre : String) : Option Substring :=
s.toSubstring.dropPrefix? pre.toSubstring
def dropPrefix? (s : String) (pre : Substring) : Option Substring :=
s.toSubstring.dropPrefix? pre
/--
If `suff` is a suffix of `s`, i.e. `s = t ++ suff`, returns the remainder `t`.
-/
def dropSuffix? (s : String) (suff : String) : Option Substring :=
s.toSubstring.dropSuffix? suff.toSubstring
def dropSuffix? (s : String) (suff : Substring) : Option Substring :=
s.toSubstring.dropSuffix? suff
/-- `s.stripPrefix pre` will remove `pre` from the beginning of `s` if it occurs there,
or otherwise return `s`. -/
def stripPrefix (s : String) (pre : String) : String :=
def stripPrefix (s : String) (pre : Substring) : String :=
s.dropPrefix? pre |>.map Substring.toString |>.getD s
/-- `s.stripSuffix suff` will remove `suff` from the end of `s` if it occurs there,
or otherwise return `s`. -/
def stripSuffix (s : String) (suff : String) : String :=
def stripSuffix (s : String) (suff : Substring) : String :=
s.dropSuffix? suff |>.map Substring.toString |>.getD s
end String

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@@ -4,5 +4,21 @@ Released under Apache 2.0 license as described in the file LICENSE.
Authors: Mario Carneiro, Yury G. Kudryashov
-/
prelude
import Init.Data.Sum.Basic
import Init.Data.Sum.Lemmas
import Init.Core
namespace Sum
deriving instance DecidableEq for Sum
deriving instance BEq for Sum
/-- Check if a sum is `inl` and if so, retrieve its contents. -/
def getLeft? : α β Option α
| inl a => some a
| inr _ => none
/-- Check if a sum is `inr` and if so, retrieve its contents. -/
def getRight? : α β Option β
| inr b => some b
| inl _ => none
end Sum

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@@ -1,178 +0,0 @@
/-
Copyright (c) 2017 Mario Carneiro. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Mario Carneiro, Yury G. Kudryashov
-/
prelude
import Init.PropLemmas
/-!
# Disjoint union of types
This file defines basic operations on the the sum type `α ⊕ β`.
`α ⊕ β` is the type made of a copy of `α` and a copy of `β`. It is also called *disjoint union*.
## Main declarations
* `Sum.isLeft`: Returns whether `x : α ⊕ β` comes from the left component or not.
* `Sum.isRight`: Returns whether `x : α ⊕ β` comes from the right component or not.
* `Sum.getLeft`: Retrieves the left content of a `x : α ⊕ β` that is known to come from the left.
* `Sum.getRight`: Retrieves the right content of `x : α ⊕ β` that is known to come from the right.
* `Sum.getLeft?`: Retrieves the left content of `x : α ⊕ β` as an option type or returns `none`
if it's coming from the right.
* `Sum.getRight?`: Retrieves the right content of `x : α ⊕ β` as an option type or returns `none`
if it's coming from the left.
* `Sum.map`: Maps `α ⊕ β` to `γ ⊕ δ` component-wise.
* `Sum.elim`: Nondependent eliminator/induction principle for `α ⊕ β`.
* `Sum.swap`: Maps `α ⊕ β` to `β ⊕ α` by swapping components.
* `Sum.LiftRel`: The disjoint union of two relations.
* `Sum.Lex`: Lexicographic order on `α ⊕ β` induced by a relation on `α` and a relation on `β`.
## Further material
See `Batteries.Data.Sum.Lemmas` for theorems about these definitions.
## Notes
The definition of `Sum` takes values in `Type _`. This effectively forbids `Prop`- valued sum types.
To this effect, we have `PSum`, which takes value in `Sort _` and carries a more complicated
universe signature in consequence. The `Prop` version is `Or`.
-/
namespace Sum
deriving instance DecidableEq for Sum
deriving instance BEq for Sum
section get
/-- Check if a sum is `inl`. -/
def isLeft : α β Bool
| inl _ => true
| inr _ => false
/-- Check if a sum is `inr`. -/
def isRight : α β Bool
| inl _ => false
| inr _ => true
/-- Retrieve the contents from a sum known to be `inl`.-/
def getLeft : (ab : α β) ab.isLeft α
| inl a, _ => a
/-- Retrieve the contents from a sum known to be `inr`.-/
def getRight : (ab : α β) ab.isRight β
| inr b, _ => b
/-- Check if a sum is `inl` and if so, retrieve its contents. -/
def getLeft? : α β Option α
| inl a => some a
| inr _ => none
/-- Check if a sum is `inr` and if so, retrieve its contents. -/
def getRight? : α β Option β
| inr b => some b
| inl _ => none
@[simp] theorem isLeft_inl : (inl x : α β).isLeft = true := rfl
@[simp] theorem isLeft_inr : (inr x : α β).isLeft = false := rfl
@[simp] theorem isRight_inl : (inl x : α β).isRight = false := rfl
@[simp] theorem isRight_inr : (inr x : α β).isRight = true := rfl
@[simp] theorem getLeft_inl (h : (inl x : α β).isLeft) : (inl x).getLeft h = x := rfl
@[simp] theorem getRight_inr (h : (inr x : α β).isRight) : (inr x).getRight h = x := rfl
@[simp] theorem getLeft?_inl : (inl x : α β).getLeft? = some x := rfl
@[simp] theorem getLeft?_inr : (inr x : α β).getLeft? = none := rfl
@[simp] theorem getRight?_inl : (inl x : α β).getRight? = none := rfl
@[simp] theorem getRight?_inr : (inr x : α β).getRight? = some x := rfl
end get
/-- Define a function on `α ⊕ β` by giving separate definitions on `α` and `β`. -/
protected def elim {α β γ} (f : α γ) (g : β γ) : α β γ :=
fun x => Sum.casesOn x f g
@[simp] theorem elim_inl (f : α γ) (g : β γ) (x : α) :
Sum.elim f g (inl x) = f x := rfl
@[simp] theorem elim_inr (f : α γ) (g : β γ) (x : β) :
Sum.elim f g (inr x) = g x := rfl
/-- Map `α ⊕ β` to `α' ⊕ β'` sending `α` to `α'` and `β` to `β'`. -/
protected def map (f : α α') (g : β β') : α β α' β' :=
Sum.elim (inl f) (inr g)
@[simp] theorem map_inl (f : α α') (g : β β') (x : α) : (inl x).map f g = inl (f x) := rfl
@[simp] theorem map_inr (f : α α') (g : β β') (x : β) : (inr x).map f g = inr (g x) := rfl
/-- Swap the factors of a sum type -/
def swap : α β β α := Sum.elim inr inl
@[simp] theorem swap_inl : swap (inl x : α β) = inr x := rfl
@[simp] theorem swap_inr : swap (inr x : α β) = inl x := rfl
section LiftRel
/-- Lifts pointwise two relations between `α` and `γ` and between `β` and `δ` to a relation between
`α ⊕ β` and `γ ⊕ δ`. -/
inductive LiftRel (r : α γ Prop) (s : β δ Prop) : α β γ δ Prop
/-- `inl a` and `inl c` are related via `LiftRel r s` if `a` and `c` are related via `r`. -/
| protected inl {a c} : r a c LiftRel r s (inl a) (inl c)
/-- `inr b` and `inr d` are related via `LiftRel r s` if `b` and `d` are related via `s`. -/
| protected inr {b d} : s b d LiftRel r s (inr b) (inr d)
@[simp] theorem liftRel_inl_inl : LiftRel r s (inl a) (inl c) r a c :=
fun h => by cases h; assumption, LiftRel.inl
@[simp] theorem not_liftRel_inl_inr : ¬LiftRel r s (inl a) (inr d) := nofun
@[simp] theorem not_liftRel_inr_inl : ¬LiftRel r s (inr b) (inl c) := nofun
@[simp] theorem liftRel_inr_inr : LiftRel r s (inr b) (inr d) s b d :=
fun h => by cases h; assumption, LiftRel.inr
instance {r : α γ Prop} {s : β δ Prop}
[ a c, Decidable (r a c)] [ b d, Decidable (s b d)] :
(ab : α β) (cd : γ δ), Decidable (LiftRel r s ab cd)
| inl _, inl _ => decidable_of_iff' _ liftRel_inl_inl
| inl _, inr _ => Decidable.isFalse not_liftRel_inl_inr
| inr _, inl _ => Decidable.isFalse not_liftRel_inr_inl
| inr _, inr _ => decidable_of_iff' _ liftRel_inr_inr
end LiftRel
section Lex
/-- Lexicographic order for sum. Sort all the `inl a` before the `inr b`, otherwise use the
respective order on `α` or `β`. -/
inductive Lex (r : α α Prop) (s : β β Prop) : α β α β Prop
/-- `inl a₁` and `inl a₂` are related via `Lex r s` if `a₁` and `a₂` are related via `r`. -/
| protected inl {a₁ a₂} (h : r a₁ a₂) : Lex r s (inl a₁) (inl a₂)
/-- `inr b₁` and `inr b₂` are related via `Lex r s` if `b₁` and `b₂` are related via `s`. -/
| protected inr {b₁ b₂} (h : s b₁ b₂) : Lex r s (inr b₁) (inr b₂)
/-- `inl a` and `inr b` are always related via `Lex r s`. -/
| sep (a b) : Lex r s (inl a) (inr b)
attribute [simp] Lex.sep
@[simp] theorem lex_inl_inl : Lex r s (inl a₁) (inl a₂) r a₁ a₂ :=
fun h => by cases h; assumption, Lex.inl
@[simp] theorem lex_inr_inr : Lex r s (inr b₁) (inr b₂) s b₁ b₂ :=
fun h => by cases h; assumption, Lex.inr
@[simp] theorem lex_inr_inl : ¬Lex r s (inr b) (inl a) := nofun
instance instDecidableRelSumLex [DecidableRel r] [DecidableRel s] : DecidableRel (Lex r s)
| inl _, inl _ => decidable_of_iff' _ lex_inl_inl
| inl _, inr _ => Decidable.isTrue (Lex.sep _ _)
| inr _, inl _ => Decidable.isFalse lex_inr_inl
| inr _, inr _ => decidable_of_iff' _ lex_inr_inr
end Lex
end Sum

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@@ -1,251 +0,0 @@
/-
Copyright (c) 2017 Mario Carneiro. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Mario Carneiro, Yury G. Kudryashov
-/
prelude
import Init.Data.Sum.Basic
import Init.Ext
/-!
# Disjoint union of types
Theorems about the definitions introduced in `Init.Data.Sum.Basic`.
-/
open Function
namespace Sum
@[simp] protected theorem «forall» {p : α β Prop} :
( x, p x) ( a, p (inl a)) b, p (inr b) :=
fun h => fun _ => h _, fun _ => h _, fun h₁, h₂ => Sum.rec h₁ h₂
@[simp] protected theorem «exists» {p : α β Prop} :
( x, p x) ( a, p (inl a)) b, p (inr b) :=
fun
| inl a, h => Or.inl a, h
| inr b, h => Or.inr b, h,
fun
| Or.inl a, h => inl a, h
| Or.inr b, h => inr b, h
theorem forall_sum {γ : α β Sort _} (p : ( ab, γ ab) Prop) :
( fab, p fab) ( fa fb, p (Sum.rec fa fb)) := by
refine fun h fa fb => h _, fun h fab => ?_
have h1 : fab = Sum.rec (fun a => fab (Sum.inl a)) (fun b => fab (Sum.inr b)) := by
apply funext
rintro (_ | _) <;> rfl
rw [h1]; exact h _ _
section get
@[simp] theorem inl_getLeft : (x : α β) (h : x.isLeft), inl (x.getLeft h) = x
| inl _, _ => rfl
@[simp] theorem inr_getRight : (x : α β) (h : x.isRight), inr (x.getRight h) = x
| inr _, _ => rfl
@[simp] theorem getLeft?_eq_none_iff {x : α β} : x.getLeft? = none x.isRight := by
cases x <;> simp only [getLeft?, isRight, eq_self_iff_true, reduceCtorEq]
@[simp] theorem getRight?_eq_none_iff {x : α β} : x.getRight? = none x.isLeft := by
cases x <;> simp only [getRight?, isLeft, eq_self_iff_true, reduceCtorEq]
theorem eq_left_getLeft_of_isLeft : {x : α β} (h : x.isLeft), x = inl (x.getLeft h)
| inl _, _ => rfl
@[simp] theorem getLeft_eq_iff (h : x.isLeft) : x.getLeft h = a x = inl a := by
cases x <;> simp at h
theorem eq_right_getRight_of_isRight : {x : α β} (h : x.isRight), x = inr (x.getRight h)
| inr _, _ => rfl
@[simp] theorem getRight_eq_iff (h : x.isRight) : x.getRight h = b x = inr b := by
cases x <;> simp at h
@[simp] theorem getLeft?_eq_some_iff : x.getLeft? = some a x = inl a := by
cases x <;> simp only [getLeft?, Option.some.injEq, inl.injEq, reduceCtorEq]
@[simp] theorem getRight?_eq_some_iff : x.getRight? = some b x = inr b := by
cases x <;> simp only [getRight?, Option.some.injEq, inr.injEq, reduceCtorEq]
@[simp] theorem bnot_isLeft (x : α β) : !x.isLeft = x.isRight := by cases x <;> rfl
@[simp] theorem isLeft_eq_false {x : α β} : x.isLeft = false x.isRight := by cases x <;> simp
theorem not_isLeft {x : α β} : ¬x.isLeft x.isRight := by simp
@[simp] theorem bnot_isRight (x : α β) : !x.isRight = x.isLeft := by cases x <;> rfl
@[simp] theorem isRight_eq_false {x : α β} : x.isRight = false x.isLeft := by cases x <;> simp
theorem not_isRight {x : α β} : ¬x.isRight x.isLeft := by simp
theorem isLeft_iff : x.isLeft y, x = Sum.inl y := by cases x <;> simp
theorem isRight_iff : x.isRight y, x = Sum.inr y := by cases x <;> simp
end get
theorem inl.inj_iff : (inl a : α β) = inl b a = b := inl.inj, congrArg _
theorem inr.inj_iff : (inr a : α β) = inr b a = b := inr.inj, congrArg _
theorem inl_ne_inr : inl a inr b := nofun
theorem inr_ne_inl : inr b inl a := nofun
/-! ### `Sum.elim` -/
@[simp] theorem elim_comp_inl (f : α γ) (g : β γ) : Sum.elim f g inl = f :=
rfl
@[simp] theorem elim_comp_inr (f : α γ) (g : β γ) : Sum.elim f g inr = g :=
rfl
@[simp] theorem elim_inl_inr : @Sum.elim α β _ inl inr = id :=
funext fun x => Sum.casesOn x (fun _ => rfl) fun _ => rfl
theorem comp_elim (f : γ δ) (g : α γ) (h : β γ) :
f Sum.elim g h = Sum.elim (f g) (f h) :=
funext fun x => Sum.casesOn x (fun _ => rfl) fun _ => rfl
@[simp] theorem elim_comp_inl_inr (f : α β γ) :
Sum.elim (f inl) (f inr) = f :=
funext fun x => Sum.casesOn x (fun _ => rfl) fun _ => rfl
theorem elim_eq_iff {u u' : α γ} {v v' : β γ} :
Sum.elim u v = Sum.elim u' v' u = u' v = v' := by
simp [funext_iff]
/-! ### `Sum.map` -/
@[simp] theorem map_map (f' : α' α'') (g' : β' β'') (f : α α') (g : β β') :
x : Sum α β, (x.map f g).map f' g' = x.map (f' f) (g' g)
| inl _ => rfl
| inr _ => rfl
@[simp] theorem map_comp_map (f' : α' α'') (g' : β' β'') (f : α α') (g : β β') :
Sum.map f' g' Sum.map f g = Sum.map (f' f) (g' g) :=
funext <| map_map f' g' f g
@[simp] theorem map_id_id : Sum.map (@id α) (@id β) = id :=
funext fun x => Sum.recOn x (fun _ => rfl) fun _ => rfl
theorem elim_map {f₁ : α β} {f₂ : β ε} {g₁ : γ δ} {g₂ : δ ε} {x} :
Sum.elim f₂ g₂ (Sum.map f₁ g₁ x) = Sum.elim (f₂ f₁) (g₂ g₁) x := by
cases x <;> rfl
theorem elim_comp_map {f₁ : α β} {f₂ : β ε} {g₁ : γ δ} {g₂ : δ ε} :
Sum.elim f₂ g₂ Sum.map f₁ g₁ = Sum.elim (f₂ f₁) (g₂ g₁) :=
funext fun _ => elim_map
@[simp] theorem isLeft_map (f : α β) (g : γ δ) (x : α γ) :
isLeft (x.map f g) = isLeft x := by
cases x <;> rfl
@[simp] theorem isRight_map (f : α β) (g : γ δ) (x : α γ) :
isRight (x.map f g) = isRight x := by
cases x <;> rfl
@[simp] theorem getLeft?_map (f : α β) (g : γ δ) (x : α γ) :
(x.map f g).getLeft? = x.getLeft?.map f := by
cases x <;> rfl
@[simp] theorem getRight?_map (f : α β) (g : γ δ) (x : α γ) :
(x.map f g).getRight? = x.getRight?.map g := by cases x <;> rfl
/-! ### `Sum.swap` -/
@[simp] theorem swap_swap (x : α β) : swap (swap x) = x := by cases x <;> rfl
@[simp] theorem swap_swap_eq : swap swap = @id (α β) := funext <| swap_swap
@[simp] theorem isLeft_swap (x : α β) : x.swap.isLeft = x.isRight := by cases x <;> rfl
@[simp] theorem isRight_swap (x : α β) : x.swap.isRight = x.isLeft := by cases x <;> rfl
@[simp] theorem getLeft?_swap (x : α β) : x.swap.getLeft? = x.getRight? := by cases x <;> rfl
@[simp] theorem getRight?_swap (x : α β) : x.swap.getRight? = x.getLeft? := by cases x <;> rfl
section LiftRel
theorem LiftRel.mono (hr : a b, r₁ a b r₂ a b) (hs : a b, s₁ a b s₂ a b)
(h : LiftRel r₁ s₁ x y) : LiftRel r₂ s₂ x y := by
cases h
· exact LiftRel.inl (hr _ _ _)
· exact LiftRel.inr (hs _ _ _)
theorem LiftRel.mono_left (hr : a b, r₁ a b r₂ a b) (h : LiftRel r₁ s x y) :
LiftRel r₂ s x y :=
(h.mono hr) fun _ _ => id
theorem LiftRel.mono_right (hs : a b, s₁ a b s₂ a b) (h : LiftRel r s₁ x y) :
LiftRel r s₂ x y :=
h.mono (fun _ _ => id) hs
protected theorem LiftRel.swap (h : LiftRel r s x y) : LiftRel s r x.swap y.swap := by
cases h
· exact LiftRel.inr _
· exact LiftRel.inl _
@[simp] theorem liftRel_swap_iff : LiftRel s r x.swap y.swap LiftRel r s x y :=
fun h => by rw [ swap_swap x, swap_swap y]; exact h.swap, LiftRel.swap
end LiftRel
section Lex
protected theorem LiftRel.lex {a b : α β} (h : LiftRel r s a b) : Lex r s a b := by
cases h
· exact Lex.inl _
· exact Lex.inr _
theorem liftRel_subrelation_lex : Subrelation (LiftRel r s) (Lex r s) := LiftRel.lex
theorem Lex.mono (hr : a b, r₁ a b r₂ a b) (hs : a b, s₁ a b s₂ a b) (h : Lex r₁ s₁ x y) :
Lex r₂ s₂ x y := by
cases h
· exact Lex.inl (hr _ _ _)
· exact Lex.inr (hs _ _ _)
· exact Lex.sep _ _
theorem Lex.mono_left (hr : a b, r₁ a b r₂ a b) (h : Lex r₁ s x y) : Lex r₂ s x y :=
(h.mono hr) fun _ _ => id
theorem Lex.mono_right (hs : a b, s₁ a b s₂ a b) (h : Lex r s₁ x y) : Lex r s₂ x y :=
h.mono (fun _ _ => id) hs
theorem lex_acc_inl (aca : Acc r a) : Acc (Lex r s) (inl a) := by
induction aca with
| intro _ _ IH =>
constructor
intro y h
cases h with
| inl h' => exact IH _ h'
theorem lex_acc_inr (aca : a, Acc (Lex r s) (inl a)) {b} (acb : Acc s b) :
Acc (Lex r s) (inr b) := by
induction acb with
| intro _ _ IH =>
constructor
intro y h
cases h with
| inr h' => exact IH _ h'
| sep => exact aca _
theorem lex_wf (ha : WellFounded r) (hb : WellFounded s) : WellFounded (Lex r s) :=
have aca : a, Acc (Lex r s) (inl a) := fun a => lex_acc_inl (ha.apply a)
fun x => Sum.recOn x aca fun b => lex_acc_inr aca (hb.apply b)
end Lex
theorem elim_const_const (c : γ) :
Sum.elim (const _ c : α γ) (const _ c : β γ) = const _ c := by
apply funext
rintro (_ | _) <;> rfl
@[simp] theorem elim_lam_const_lam_const (c : γ) :
Sum.elim (fun _ : α => c) (fun _ : β => c) = fun _ => c :=
Sum.elim_const_const c

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@@ -135,10 +135,6 @@ Both reduce to `b = false ∧ c = false` via `not_or`.
theorem not_and_of_not_or_not (h : ¬a ¬b) : ¬(a b) := h.elim (mt (·.1)) (mt (·.2))
/-! ## not equal -/
theorem ne_of_apply_ne {α β : Sort _} (f : α β) {x y : α} : f x f y x y :=
mt <| congrArg _
/-! ## Ite -/
@@ -388,17 +384,6 @@ theorem forall_prop_of_false {p : Prop} {q : p → Prop} (hn : ¬p) : (∀ h' :
end quantifiers
/-! ## membership -/
section Mem
variable [Membership α β] {s t : β} {a b : α}
theorem ne_of_mem_of_not_mem (h : a s) : b s a b := mt fun e => e h
theorem ne_of_mem_of_not_mem' (h : a s) : a t s t := mt fun e => e h
end Mem
/-! ## Nonempty -/
@[simp] theorem nonempty_prop {p : Prop} : Nonempty p p :=

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@@ -1,10 +1,10 @@
theorem Sum.inl_ne_inr' : inl a inr b := nofun
theorem Sum.inl_ne_inr : inl a inr b := nofun
theorem Sum.inr_ne_inl' : inr b inl a := nofun
theorem Sum.inr_ne_inl : inr b inl a := nofun
theorem Sum.inl_ne_inr'' : inl a inr b := by nofun
theorem Sum.inl_ne_inr' : inl a inr b := by nofun
theorem Sum.inr_ne_inl'' : inr b inl a := by nofun
theorem Sum.inr_ne_inl' : inr b inl a := by nofun
def f (a b : Bool) (_ : Sum.inr b Sum.inl a) : Nat := 0