Each semester we host one to two visitors. This semester's visitors are still to be determined. Check the list of previous visitors.

Class schedule: the page will be regularly updated. Check it out regularly for announcements of required/recommended reading material, homework, etc.

General Information

Prereq: CSCE235, Discrete Structures (exceptionally this year).

Course description: Constraint satisfaction has emerged as a powerful approach to articulate and solve many problems in computer science, engineering, and management.  It is now the basis for new programming languages and innovative commercial systems for production scheduling, product configuration, personnel planning and timetabling, etc.  The course will review the foundations of constraint satisfaction and the basic mechanisms for constraint propagation.  It will cover aspects of modeling and representation, and will examine islands of tractability and methods for theoretical and empirical evaluation of problem `difficulty.'  If time permits, we will examine new methods for decomposition and symmetry identification, designed to overcome the complexity barrier and to support interactions with users.

Lectures: Monday, Wednesday, Friday from 2:30 p.m. to 3:20 p.m.
Location: Avery Hall, Room 111.

Make-up Class/Recitation: Monday from 5:00 p.m. to 5:50 p.m.
Location: Avery Hall, Room 111 (moved from AvH 20).

Instructor:   Prof.  Berthe Y. Choueiry
      Office location: Room 360, Avery Hall,
      choueiry AT, tel: (402)472-5444.
      Office hours: Wednesday/Friday 3:30-4:30 p.m. or by appointment.

Volunteer GTA's & Office Hours:

Mr. Shant Karakashian
Office hours held in Student Resource Center.
Hours: Thursday 9:00 a.m. -- 11:00 a.m.
Also by appointment

Mr. Robert Woodward
Office hours held in Student Resource Center.
Hours: Thursday 5:00 p.m. -- 6:00 p.m. & Friday 9:00 a.m. -- 10:00 a.m.
Also by appointment

"Constraint Processing" by Rina Dechter, 1st edition. The textbook will not be followed sequentially, but should be used for reference.

For quick response, email  Your message will be forwarded to both TA and instructor.

Important note:We do not have a GTA allocated to this class. We may have a UTA (undergraduate TA) with likely little experience in the subject matter and who will mainly help with administrative matters. The two GTA's are volunteers: it is best to talk to them during their office hours. Please send all questions to cse421 AT for a quick response.

Topics include but are not restricted to:

  • Properties, computational complexity, and practical importance.
  • Global and local consistency: algorithms, properties and computational complexity.
  • Islands of tractability for minimality and global consistency.
  • Intelligent backtracking.
  • Look-ahead techniques.
  • Ordering heuristics.
  • Theoretical and empirical comparison of hybrid search algorithms.
  • Phase transition.
  • Modeling and reduction methods between representations.
  • If time permits: Decomposition. Symmetries and their approximations. Temporal constraint networks. Stochastic search. Reformulation and abstraction. Dynamic/conditional Constraint Satisfaction (CSP). Constrained Optimization Problem (COP).
  • Other, depending on class interests.


  • Rina Dechter, Constraint Processing, 2003, Morgan Kauffmann.  Available from bookstore.
  • Edward Tsang, Foundations of Constraint Satisfaction. Available from instructor and on reserve at the Math Library in Avery.
  • Technical papers given by instructor or available from the Electronic Reserve at the Love Library.

Last modified: Thu Jan 13 22:55:31 CST 2011