Let us assume that we wish to prove something with a conjecture. We do not know whether it is true or false. But we assume that it is true and we arrive at our proof. After that we assume that it is false and we still arrive at the same conclusion. Thus we conclude that the thing we were proving must be true.
Here is the justification of the proof.
Thus, by the above paragraph:
Apply contrapositive to (1):
Apply syllogism (chain rule) between (2) and (3):
Assume is false thus,
is false thus contradiction.
Thus, is true.
But my question remains can you possibly think of something which you can prove like this? If you can this would be one elegant and amazing proof.