original.name="UnionType_Valid_23"
======
>>> main.whiley
type IntList is {int op, bool[] rest} | {int op, int mode}
function f(IntList y) -> IntList:
return y
public export method test() :
IntList x = (IntList) {op: 1, rest: [false]}
if 0 == 10:
x = {op: 0, rest: [false]}
if x is {int op, bool[] rest}:
x.op = 123
else:
x.op = 123
assume f(x) == {op: 123, rest: [false]}
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