What are these symbols?

Asaf Karagila discusses some of the symbols used in Logic and Set Theory.

Asaf is a UKRI Future Leaders Fellow.

Asaf's blog - https://karagila.org

More videos and Numberphile podcast featuring Asaf - https://www.youtube.com/playlist?list=PLt5AfwLFPxWJyt0zdvzvDoeL_8pqO0S7p

* A set theorist's clarification from Asaf commenting on Brady's simplified animations... "By {Primes} we mean the set {2,3,5,7,11,13,...} of prime numbers, rather than the set whose element is the set of prime numbers"