original.name="Parsing_Invalid_12"
======
>>> main.whiley
function f(int x) -> (int r):
    switch(x):
     case 1:
      return 0
     case 1:
      return 1
    //
    return 0
---
E313 main.whiley 5,10
=====
>>> main.whiley 3:4
     case 0:
>>> main.whiley 9
public export method test():
    assume f(0) == 0
    assume f(1) == 1
    assume f(2) == 0
---