original.name="TypeEquals_Valid_2"
======
>>> main.whiley


type expr is {int op, expr lhs} | {int[] err}

function f(expr e) -> int:
    if e is {int[] err}:
        return |e.err|
    else:
        return -1

public export method test() :
    int x = f({err: "Hello World"})
    assume x == 11
    x = f({op: 1, lhs: {err: "Gotcha"}})
    assume x == -1

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