CMPSCI 601: Theory of Computation

David Mix Barrington

Spring, 2003

This is the home page for CMPSCI 601. CMPSCI 601 is the graduate core course in the theory of computation and will deal with formal languages, computability, logic, and complexity theory.

Important Course Material:

• Lecture Notes Directory
• Homework Assignment Directory (with HW#8)
• Exam Directory (with practice final and solutions)
• Questions and Answers
• Syllabus

Announcements (28 August 2003):

• I have moved the web site for the summer video version of the course here, and started a new web site for the fall version here.

• I am offering this course again during the summer term through the PEEAS program, using videotaped lectures from this Spring 2003 offering. This is the main web page for the summer version of the course.

• The final exam has now been posted, together with solutions.

• I have received and graded the final exams for the nine off-campus students who took it. The scores, in descending order, were 68, 66, 65, 62, 57, 56, 54, 47, and 41. For overall course grades these students received one AB, four B's, three BC's, and a C -- they have been emailed with their individual results.

• Here is a summary of the results of the final for the 39 on-campus students.

  • The A range was 80+, AB range 64-79, B range 48-63, BC range 32-47.

  • There were seventeen A's, with the top scores being a 98, a 96, a 93 and two 92's. There were eleven AB's, six B's, and five BC's.

  • The course grades, with the midterm and homework factored in, were generally higher than the final exam grades. There were 22 A's, 11 AB's, five B's, and an incomplete. As it happens, the five on-campus B's were the same five who scored less than 50 points on the final exam.

• Solutions to HW#8 are now available online.

• On-campus finals are now graded. I will hand them back in person in my office. I'll next be in today from around 1:30 to 5:00. Graded homework will be available in the main office in the pickup box.

• There is a correction and a clarification to the crib sheet included in the off-campus final exams:
  • The language K, as it has bee all term, is defined to be {n: n is in L(M_n), not the complement of this language which is K-bar.
  • A more precise definition of the language VALCOMP_M is {w: ∃ x: w describes an accepting computation of M on x}. Here M is a one-tape Turing machine fixed for the language.

• The Q&A page now has some questions relevant to the final, some concerning the practice final and its solutions.

• The solution to the practice final is now up.

• I have given the final exam to the PEEAS office, who will mail it to off-campus students to arrive on Mon 19 May, just as the on-campus students are taking theirs. I need the off-campus exams back by Tue 27 May in order to file grades the next day. Off-campus students may fax them that day or send them by overnight service to arrive that day. Note that Mon 26 May is a national holiday.

• Paper copies of the solutions to HW#8 are now available in the CMPSCI main office. Kazu has posted HW#7 solutions linked from his page.

• Notes for the last lecture are now up.

• To answer a common question as HW#8 comes due, yes, it is true that only the best seven of your eight homeworks count. So if you are not likely to do as well as the worst of your first seven, you have no incentive to hand in #8. Understanding the solutions to #8, though, will be important on the final.

• The practice final is now up. The final exam will have the same format and cover about the same material.

• The HW#8 assignment is now up. I have extended the due date of HW#8 to Wednesday 14 May for on-campus students. I will announce the due date for off-campus students after consulting with Kazu, but it will be no earlier than Monday 19 May.

• Note that the web site contains postscript versions of each lecture as well, named, e.g., "27.ps" rather than "27.pdf" in the same directory.

• The pointer on the syllabus to the original Chandra-Kozen-Stockmeyer article on alternation, actually works and gets you a pdf file.

• I've posted the midterm exam and solutions for the midterm in the exam directory. The solutions include notes on some of the more common wrong answers I received.

• Our final exam is on Monday 19 May from 8:00-10:00 a.m. in AEBN 119, as indicated on the University final exam schedule. I've just fixed an incorrect date that has been on the syllabus all term. (Apologies for the delay, especially to the student who pointed out my mistake a month ago!)

• I've received and graded midterm exams from nine off-campus students. The scores, in sorted order, were 39, 43, 44, 47, 51, 54, 63, 66, and 67. (See below for the scale and the distribution of on-campus scores.) I will send back the exams by mail, but if you would like a breakdown of your score and comments by email please let me know before the start of next week.

• The HW#7 assignment is now up.

• I have graded the 41 in-class midterms and will return them in class tomorrow. Scores were widely distributed but I thought the test did a good job of showing what you could and couldn't do. The median grade was a 68, an AB. There were two 99's and a 98, and a 26. More specifically:
  • 90-99 (high A ): 5
  • 80-89 (low A ): 7
  • 70-79 (high AB): 8
  • 60-69 (low AB): 9
  • 50-59 (high B ): 5
  • 40-49 (low B ): 4
  • 30-39 (high BC): 2
  • 20-29 (low BC): 1

• The Question and Answer Page now has several questions on the practice midterm and the material for the real midterm.

• Midterm exams for off-campus students will be given to the PEEAS office midday on Monday, just after the off-campus students have taken the exam. Off-campus students should arrange to take the exam on or about 8 April 2003, before viewing the lecture of 3 April 2003.

• My solution to the practice midterm is now posted.

• My solution to HW#3 is posted here and Kazu's solutions to HW#1 and HW#2 are linked from Kazu's page. There will be no posted solutions for HW#4.

• TA Kazu Hirata has established a web page for course-related material. Off-campus students may confirm receipt of their homeworks there.

• Remember that the lecture notes are very similar to last year's notes, which are available for the whole term here.

• The question and answer page logs questions of general interest that I receive, primarily about the current homework assignment.

In Spring 2002 this course was taught by Prof. Immerman, and I will be modeling this term's offering closely on his. The web site for his offering is still available here.

In particular, the two textbooks for the course are the same. These are:

• Papadimitriou, Computational Complexity (Addison-Wesley, 1994)
• Barwise and Etchemendy, Language, Proof, and Logic (University of Chicago Press, 2002) (Same as earlier edition through Seven Bridges Press, 1999 but the 1999 edition is out of print)

Both texts are now available for sale at Jeffrey Amherst Bookshop in downtown Amherst. The B&E book ("LPL") will be used for roughly the middle third of the course, beginning with Lecture #10 on Mon 3 Mar.

Last modified 28 August 2003