In this case, the values whose parity we're considering are the number of 1s in each digit place of our binary sums.
在这个案例中,我们考虑奇偶性的值就是加总中两个位数中 1 的个数。
TED-Ed(视频版)
In this case, the values whose parity we're considering are the number of 1s in each digit place of our binary sums. And that's why we can say that 2 and 0, both even numbers, can be treated as equivalents.