9 lines
289 B
Text
9 lines
289 B
Text
@[simp] def Stream.hasLength [Stream stream value] (n : Nat) (s : stream) : Bool :=
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match n, Stream.next? s with
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| 0, none => true
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| n + 1, some (_, s') => hasLength n s'
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| _, _ => false
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#check @Stream.hasLength._eq_1
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#check @Stream.hasLength._eq_2
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#check @Stream.hasLength._eq_3
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