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14 lines
398 B
Idris
14 lines
398 B
Idris
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module Issue2573
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||| Define foo, the identity function in disguise
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foo : Ord a => (x : a) -> a
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foo x = if x < x then x else x
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||| Assume that foo x = x
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eq : Ord a => (a -> a) -> (x : a) -> Issue2573.foo x = x
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eq f x = believe_me ()
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||| Prove that if x < y then (foo x) < y
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prf : Ord a => (a -> a) -> (x, y : a) -> x < y = True -> Issue2573.foo x < y = True
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prf f x y lt = rewrite (eq f x) in lt
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