No, it does not comply with the Rule. Further in the chapter there is another definition of EVEN, where Rule 2 states : "If x and y are both in EVEN, then so is x + y", When using this definition 4 + 6 would be correct.
If I remember correctly, the question stated specifically to use the definition on a certain page. That was the first definition with the x = even, then x + 2 = even. The example that Elize is quoting, was not on the same page and I ignored that version of Rule 2.