Practical information Thursdays, from 2pm to 4pm Office hours by appointment, in room 234, Ludwigstrasse 31, second floor
You can find the text book here (credits to Marco).
WE POSTPONE AGAIN THE MAKEUP SESSION because of a lack of quorum. Let's discuss this next Thursday.
Here's another cool video. Very instructive! (Credits to Nico González Albornoz)
Lectures
1. Introduction: What Gödel's Theorems Say27/4 Read: Smith's (2007), Chapter 1.
2. Decidability and Enumerability27/4  4/5 Read: Smith's (2007), Chapter 2. Exercises: about functions (all of them except 4), effective computability (all of them except exercise 5), and enumerability.
3. Axiomatised formal theories
11/5 Read: Smith's (2007), Chapter 3.
Exercises: about formal theories (in particular, exercises 1 and 4).
4. Expressing and Capturing Numerical Properties
18/5 Read: Smith's (2007), Chapter 4: Capturing Numerical Properties. Exercises: about the language of arithmetic.
5. Robinson Arithmetic Q
1/6  22/6 Read: Smith's (2007), Chapters 8 and 9. Exercise: read and understand chapters 5 and 6 to briefly explain their content in class
6. Robinson Arithmetic Q and Peano Arithmetic PA
29/6 Read: Smith's (2007), Chapter 10. Exercises: about sufficiently expressive/strong theories and induction.
Course description
The course consists in a detailed exposition of Gödel's first and second incompleteness theorems, and their respective proofs. The first result shows that any theory extending elementary arithmetic is incomplete, this is, there will always be a sentence in the language of the theory that the theory neither proves nor refutes. Gödel's second incompleteness result establishes that no consistent theory extending elementary arithmetic can prove its own consistency. The exposition is carried out in two steps. First, an introduction to firstorder arithmetic is given. Students are presented with the following: firstorder axiomatic theories, the language of firstorder arithmetic, L, firstorder theories of arithmetic BA (for "Baby Arithmetic"), Q (Robinson Arithmetic), and PA (for "Peano Arithmetic"), the enumerability and denumerability of sets, the recursivity, semirecursivity, definability in L, and representability in an axiomatic theory formulated in L, of a subset of natural numbers or a function from natural numbers to natural numbers, the standard model of L, arithmetical truth, the arithmetical hierarchy, and (primitive) recursive functions. The second half of the course consists of a presentation of modern versions of Gödel's proofs of both incompleteness results, followed by a reflection on their consequences. Students are introduced to Q's Sigma1completeness, Gödel's coding technique and the arithmetisation of syntax, the diagonalisation lemmata, Gödel sentences, Löb's derivability conditions, and reflection principles.
Course material  Lecture notes
 Smith's An Introduction to Gödel's Theorems
Preparing for the course Here's an informal introduction to Gödel's Incompleteness Theorems that could be useful to read before the before the course begins: Nagel & Newman's Gödel's Proof
 Here's a funny video
Bibliography  Boolos, G., Burgess, J. & Jeffrey, R. (2007) Computability and Logic, Cambridge University Press, fifth edition.
 Gödel, K. (1931) "Über formal unentscheidbare Sätze der Principia Mathematica und verwandter Systeme, I" ("On Formally Undecidable Propositions of Principia Mathematica and Related Systems"), Monatshefte für Mathematik und Physik 38: 173–198. Reprinted in Gödel (1986), pp. 144–195.
 ——(1986) Collected Works. I: Publications 1929–1936, S. Feferman, S. Kleene, G. Moore, R. Solovay, and J. van Heijenoort (eds.), Oxford University Press.
 Nagel, E. & Newman, J. R. (2001) Gödel's Proof, New York University Press, revised edition.
 Smith, P. (2007) An Introduction to Gödel's Theorems, Cambridge University Press.
