whiley_test_file 0.6.2

original.name="Coercion_Valid_12"
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>>> main.whiley
type pos is (int x) where x >= 0
type neg is (int x) where x < 0

type R1 is {pos|neg f}

function f({pos f} x) -> (R1 r)
ensures r == x:
    return x

public export method test():
    assert f({f:0}) == {f:0}
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