Yo dawg, I heard you like conditional proofs, so I got you conditional proofs for your conditional proofs.

**Takeaway Points**

- You can nest conditional proofs or proofs by contradiction with each other or themselves. For example, if you are in the middle of a conditional proof and believe that a proof by contradiction would be useful to advance to your next step, you may begin a proof by contradiction within the conditional proof.
- For the proof within a proof, indent the steps even further.
- As before, you cannot use lines from closed proofs.
- You can use any line from an open proof, regardless of the level. So if you are working on a proof by contradiction within a conditional proof, any lines you have in the conditional proof are fair game.
- You may continue to nest proofs as much as you want as long as you follow the above rules.