This is true as the above derivation for a and b of opposite parity is an if and only if statement.

这是正确的，因为上面对a和b 的奇偶性的推导是一个当且仅当命题。

youdao

This is true as the above derivation for a and b of opposite parity is an if and only if statement.

这是正确的，因为上面对a和b 的奇偶性的推导是一个当且仅当命题。

youdao