Math 39 Homework #25 Gödel's proof is hard. Nagel & Newman

	Quiz Remember that we have a quiz on Monday 11/23 on Lectures 22 - 25.

	Reading Read what we will cover in the next class: TBA

	Problems The following problems are due by the beginning of class on Monday 11/23. Hamilton 6.4 (p. 150) #15, 16, 17. Hamilton 6.5 (p. 155) #18 Note that in this problem, Hamilton's U is our G from class. Let G be the Gödel sentence which is true but unprovable. Is Cn(PA U {G}) complete? Is Cn(PA U {~G}) complete? Informally explain (i.e., in the spirit of Crossley), the proof of Gödel's Second Incompleteness Theorem. (This is one of the proofs that I expect you to know and know really well.)