original.name="Property_Valid_2"
======
>>> main.whiley
property nat_a(int x) -> (bool r):
    return x >= 0

property nat_b(int x) -> (bool r):
    return x >= 0

function id(int x) -> (int y)
requires nat_a(x)
ensures nat_b(y):
    return x


public export method test():
    assume id(0) == 0
    assume id(1) == 1
    assume id(2) == 2


---