14 lines
392 B
Text
14 lines
392 B
Text
inductive Vec (α : Type) : Nat → Type where
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| nil : Vec α 0
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| cons : ∀ {n}, α → Vec α n → Vec α (n + 1)
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inductive Tree : Type where
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| branch : ∀ {n}, Vec (Option Tree) n → Tree
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theorem die : Tree → True
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| .branch v =>
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let rec loop {n} : Vec (Option Tree) n → True
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| .nil => ⟨⟩
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| .cons none _ => ⟨⟩
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| .cons (some t) _ => die t
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loop v
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