3f548edcd7
When updating Std, be careful that not every lemma has been upstreamed, so we need to be careful to only delete things that have already been declared.
7 lines
315 B
Text
7 lines
315 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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def Vector.nth : ∀{n}, Vector α n → Fin n → α
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| n+1, Vector.cons x xs, ⟨ 0, _⟩ => x
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| n+1, Vector.cons x xs, ⟨k+1, h⟩ => xs.nth ⟨k, Nat.lt_of_add_lt_add_right h⟩
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