11 lines
314 B
Text
11 lines
314 B
Text
inductive Vector (α : Type u): Nat → Type u where
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| nil : Vector α 0
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| cons (head : α) (tail : Vector α n) : Vector α (n+1)
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namespace Vector
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def nth : Vector α n → Fin n → α
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| cons x xs, ⟨0, _⟩ => x
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| cons x xs, ⟨k+1, h⟩ => xs.nth ⟨k, Nat.le_of_succ_le_succ h⟩
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attribute [simp] nth
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