original.name="Coercion_Valid_10"
======
>>> main.whiley
type pos is (int x) where x >= 0
type neg is (int x) where x < 0
function f(pos x) -> (pos[]|neg[] r):
return [x]
function g(neg x) -> (pos[]|neg[] r):
return [x]
public export method test():
//
assume f(1) == [1]
//
assume g(-1) == [-1]
---