@guigus,
2. And yet, the truth of a falsehood is the truth that the falsehood is false which is not the falsehood itself.
3. So the truth of a falsehood must be different from the falsehood itself but not different from itself because the truth of the falsehood of a falsehood is not itself a falsehood but rather a truth.
3. The truth of a truth makes nothing untrue except the opposite of itself which is not itself.