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19 lines
471 B
Idris
19 lines
471 B
Idris
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||| An example implementation for the Tolerance relation.
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module Data.Nat.Order.Relation
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import Control.Relation
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Adjacent : (a, b : Nat) -> Type
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Adjacent a b = Either (a = b) $ Either (a = S b) (b = S a)
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Reflexive Nat Adjacent where
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reflexive = Left Refl
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Symmetric Nat Adjacent where
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symmetric (Left x_eq_y) = Left $ sym x_eq_y
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symmetric (Right $ Left prf) = Right $ Right prf
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symmetric (Right $ Right prf) = Right $ Left prf
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Tolerance Nat Adjacent where
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