e31b17484a
@Kha The new `rational.lean` test shows their usefulness. We just define the monorphic version and a coercion, and get a bunch of `HAdd` instances for free.
37 lines
586 B
Text
37 lines
586 B
Text
structure Rat where
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num : Int
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den : Nat
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pos : den > 0
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instance (n : Nat) : OfNat Rat n where
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ofNat := {
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num := n
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den := 1
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pos := decide!
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}
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instance : Add Rat where
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add a b := {
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num := a.num * b.den + b.num * a.den
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den := a.den * b.den
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pos := sorry
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}
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instance : Coe Int Rat where
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coe n := {
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num := n
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den := 1
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pos := decide!
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}
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def f1 (x : Rat) (n : Nat) : Rat :=
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x + n + 1
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def f2 (x : Rat) (n : Nat) : Rat :=
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1 + x + n
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def f3 (x : Rat) (n : Nat) : Rat :=
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1 + n + x + 2
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def f4 (x : Rat) (n : Nat) : Rat :=
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n + 1 + x + n
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