Thanks, I missed the point that this was related to the GitHub repository. Integer addition and multiplication are associative and commutative, even in the pre

Thanks, I missed the point that this was related to the GitHub repository. Integer addition and multiplication are associative and commutative, even in the presence of two's complement wraparound. So this transformation is valid. I don't have a source to point you to, though. I'd be interested in one, if anyone has one. (Or just a proof, if it fits here.)