original.name="Switch_Invalid_1"
======
>>> main.whiley
function f(int x) -> int:
    switch x:
        case 1:
            return 0
        case 2:
            return 3
        case 1:
            return -1
    return 10
---
E313 main.whiley 7,13
=====
>>> main.whiley 7:9
>>> main.whiley 8
public export method test():
    assume f(1) == 0
    assume f(2) == 3
    assume f(0) == 10
    assume f(4) == 10
---