Godel's 1st Incompleteness Theorem - Proof by Diagonalization https://www.youtube.com/watch?v=PpSxqde0af4 https://www.youtube.com/watch?v=PpSxqde0af4 This is

Godel's 1st Incompleteness Theorem - Proof by Diagonalization https://www.youtube.com/watch?v=PpSxqde0af4 https://www.youtube.com/watch?v=PpSxqde0af4 This is another good exposition.