original.name="Define_Valid_4"
======
>>> main.whiley
type codeOp is (int x) where 1 <= x && x <= 4
type code is {codeOp op, int[] payload}
function f(codeOp x) -> code:
code y = {op: x, payload: [0]}
return y
public export method test() :
assume f(1) == {op:1, payload: [0]}
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