The purpose of asking someone to check or confirm your work on a proof is to ensure the accuracy and validity of your proof. It is always helpful to have a second set of eyes look over your work to catch any mistakes or errors that you may have missed.
You should ask someone who has expertise in the field of the proof you are working on. This could be a fellow scientist, a professor, or a mentor who has experience in the specific topic you are working on.
You should first make sure that you have thoroughly reviewed and checked your proof yourself. Once you are confident in your work, you can ask someone else to check or confirm it. It is also helpful to have a clear and concise presentation of your proof, with all steps and explanations clearly laid out.
If the person checking or confirming your work finds mistakes, it is important to listen to their feedback and make necessary revisions to your proof. It is also helpful to ask for specific explanations on where you went wrong and how to improve your proof.
Yes, it is perfectly acceptable to ask multiple people to check or confirm your work on a proof. In fact, it is often recommended to get multiple perspectives and feedback to improve the accuracy and clarity of your proof.