As we know, contrapositive symmetry is the tautology in classical logic.

众所周知，在古典逻辑中，逆否对称性是永真公式。

youdao

As we know, contrapositive symmetry is the tautology in classical logic.

众所周知，在古典逻辑中，逆否对称性是永真公式。

youdao