e7f4f98071
This PR fixes a stack overflow that occurs when constructing a proof term in `grind`. Closes #11081
79 lines
2.5 KiB
Text
79 lines
2.5 KiB
Text
namespace List
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protected def diff {α} [BEq α] : List α → List α → List α
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| l, [] => l
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| l₁, a :: l₂ => if l₁.elem a then List.diff (l₁.erase a) l₂ else List.diff l₁ l₂
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def Subperm (l₁ l₂ : List α) : Prop := ∃ l, l ~ l₁ ∧ l <+ l₂
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open Perm (swap)
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theorem Perm.subperm_left {l l₁ l₂ : List α} (p : l₁ ~ l₂) : Subperm l l₁ ↔ Subperm l l₂ :=
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sorry
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theorem Sublist.subperm {l₁ l₂ : List α} (s : l₁ <+ l₂) : Subperm l₁ l₂ := sorry
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theorem Subperm.perm_of_length_le {l₁ l₂ : List α} :
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Subperm l₁ l₂ → length l₂ ≤ length l₁ → l₁ ~ l₂ :=
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sorry
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end List
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variable {α : Type} [DecidableEq α] {l₁ l₂ : List α}
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open List
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/--
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error: `grind` failed
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case grind.1.1.1.1.1.1.1.1.1
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α : Type
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inst : (a b : α) → Decidable (a = b)
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l₁ l₂ : List α
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hl : l₂.Subperm l₁
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p : α → Bool
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h : ¬countP p l₁ = countP p (l₁.diff l₂ ++ l₂)
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w : α
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h_2 : ¬count w (l₁.diff l₂ ++ l₂) = count w l₁
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w_1 : α
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h_4 : ¬count w_1 l₁ = count w_1 (l₁.diff l₂ ++ l₂)
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left : l₂ ⊆ l₁
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right : ∀ {a : α}, a ∈ l₂ → a ∈ l₁
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left_1 : filter p l₂ <+ filter p l₁
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w_2 : List α
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left_2 : w_2 <+ l₁
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right_2 : filter p l₂ = filter p w_2
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w_3 : List α
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left_3 : w_3 <+ l₁
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right_3 : filter p l₂ = filter p w_3
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h_9 : (filter p l₂).length = (filter p l₁).length
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w_4 : α
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h_11 : ¬count w_4 (l₁.diff l₂ ++ l₂) = count w_4 l₂
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w_5 : α
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h_13 : ¬count w_5 l₂ = count w_5 (l₁.diff l₂ ++ l₂)
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left_4 : l₁.diff l₂ ~ l₁
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right_4 : ∀ (a : α), count a (l₁.diff l₂) = count a l₁
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w_6 : α
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h_16 : ¬count w_6 (l₁.diff l₂ ++ l₂) = count w_6 (l₁.diff l₂)
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w_7 : α
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h_18 : ¬count w_7 (l₁.diff l₂) = count w_7 (l₁.diff l₂ ++ l₂)
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left_5 : l₁.diff l₂ ~ l₂
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right_5 : ∀ (a : α), count a (l₁.diff l₂) = count a l₂
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left_6 : l₂ ~ l₁
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right_6 : ∀ (a : α), count a l₂ = count a l₁
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left_7 : l₂ ~ l₁.diff l₂
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right_7 : ∀ (a : α), count a l₂ = count a (l₁.diff l₂)
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left_8 : l₁ ~ l₁.diff l₂
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right_8 : ∀ (a : α), count a l₁ = count a (l₁.diff l₂)
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left_9 : l₁ ~ l₂
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right_9 : ∀ (a : α), count a l₁ = count a l₂
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⊢ False
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-/
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#guard_msgs in
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theorem countP_diff (hl : Subperm l₂ l₁) (p : α → Bool) :
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countP p l₁ = countP p (l₁.diff l₂ ++ l₂) := by
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grind -verbose [
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List.Perm.subperm_left,
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List.Sublist.subperm,
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List.Subperm.perm_of_length_le,
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List.Perm.countP_congr
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]
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