You will simply need to provide proofs for four properties of set theory.
- You need to be a native English speaker.
- You need to have studied or to be studying mathematics in university.
- You need to have already performed proofs in set theory in the past (although I don't expect you to be an expert).
Deadline: Deliver by the end of the day (this shouldn't take more than 10-15 minutes of your time anyway).
Budget: 20€, no more.