original.name="Function_Valid_11"
======
>>> main.whiley
type fr8nat is (int x) where x > 0
type fr8neg is (int x) where x < 0

function f(fr8nat y) -> bool:
    return true

function f(fr8neg x) -> bool:
    return false

public export method test() :
    fr8nat x = 1
    assume f(x) == true
    fr8neg y = -1
    assume f(y) == false

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