Semantics of Programming Languages

Prof. Tobias Nipkow, Wintersemester 2012/13

• Module: IN2055
• Lectures: Tuesday 8:30 - 10:00 in MI 00.07.014, Friday 10:30 - 12:00 in MI 00.07.014
• Exercises: Tuesday 10:15 - 11:45 in MI 03.13.010
• Start: 16.10.2011.
• Tutors: Andrei Popescu Peter Lammich

On this page: News Lecture and Exercises Homework Aims Important notice Literature

News

• The written exam
  • You will be allowed to use 2 handwritten or printed A4 sheets of paper, but nothing else.
  • A few questions will be Isabelle-specific, but most of them will deal with semantics.
  • Proofs must be detailed and readable but need not conform exactly to the Isabelle syntax. Major proof steps, especially inductions, need to be stated explicitly. Minor proof steps (corresponding to by simp, by blast etc) need not be justified if you think they are obvious, but you should say which facts they follow from.
  • The questions will all be formal (you need not write an essay) but will not all be proofs but also definitions, calculations etc.
• Here is the address of the course mailing list Mailing list
• Please bring your laptop, ideally with installed Isabelle-2012, to the exercises
• See home page of WS 10/11 for some student feedback and a presentation about the course.

Homework

Homework is the heart and soul of this course.

• Solved homeworks should be submitted via e-mail to one of the tutors:

  uuomulyahoo.com or lammichin.tum.de

  Submission Guidelines

  The subject line of the email should contain the string "[Semantics]". Please send a mail with only a single .thy file attached (no archives please). You can always solve all parts of the homework in one theory file! The filename should have the form FirstnameLastname.thy, or FirstnameMiddlenameLastname.thy, or Firstname{Von,Zu,Whatsoever}Lastname.thy (Notice capitalization). This submission format saves us from unpacking and renaming dozens of files manually.

  The latest submission date is given on each exercise sheet. Late submissions will not be graded! If you have a good excuse (such as being very sick), you should contact the tutors before the deadline.

• Each homework will get 0 to 10 points, depending on the correctness and quality of the solution.
• Discussing ideas and problems with others is encouraged. When working on homework problems, however, you need to solve and write up the actual solutions alone. If you misuse the opportunity for collaboration, we will consider this as cheating. Plagirizing somebody else's homework results in failing the course immediately. This applies for both parties, that is, the one who plagiarized and the one who provided his/her solution.
• Important: homeworks are graded and have a 40% share of the final grade.

Aims

The aim of this course will be to introduce the structural, operational approach to programming language semantics. It will show how this formalism is used to specify the meaning of some simple programming language constructs and to reason formally about semantic properties of programs and of tools like program analyzers and compilers. For the reasoning part the theorem prover Isabelle will be used.

• be familiar with rule-based presentations of the operational semantics of some simple imperative program constructs,
• be able to prove properties of an operational semantics using various forms of induction and
• be able to write precise formal proofs with the theorem prover Isabelle.

Important notice

• You must be familiar with the basics of some functional programming language like Haskell, Objective Caml, Standard ML or F# (as taught, for example, in Introduction to Informatics 2). For motivated students who do not have the necessary background yet: There are many introductions to functional programming available online, for example the first 6 chapters of Introduction to Objective Caml.
• You must haven taken some basic course in discrete mathematics where you learned about sets, relations and proof principles like induction (as taught, for example, in Discrete Structures).
• You need not be familiar with formal logic but you must be motivated to learn how to write precise and detailed mathematical proofs that are checked for correctness by a machine, the theorem prover Isabelle.
• At the end of the course there will be a written or oral examination, depending on the number of students. Throughout the course there will be homework assignments. They will involve the use of Isabelle and will be graded. The final grade will combine the grades from the examination (60%) and the homework (40%).
• All lectures are in English.

Literature

• Hanne Riis Nielson, Flemming Nielson: Semantics with Applications: A Formal Introduction.
• Glynn Winskel: The Formal Semantics of Programming Languages. MIT Press.
• Tobias Nipkow, Lawrence Paulson, Markus Wenzel: Isabelle/HOL. A Proof Assistant for Higher-Order Logic.