CMPSCI 601: Theory of Computation

David Mix Barrington

Spring, 2004

Under Construction!

To see the Spring 2003 CMPSCI 601 home page look here.

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 (under construction!):

• Lecture Notes Directory (with Lecture 27)
• Homework Assignment Directory (with HW#8)
• Exam Directory (empty so far)
• Questions and Answers (with some on HW#8)
• Syllabus (not ready yet)

Announcements (14 May 2004):

• (14 May) Hardcopy HW#8 solutions are in the CMPSCI 601 pickup box in the CMPSCI main office.

• (11 May) Ok, Lecture 27 notes are up.

• (11 May) Some questions and answers on HW#8 are up. Lecture notes for tomorrow's review lecture will follow later tonight.

• (9 May) Lecture 26 is up.

• (6 May) The HW#8 assignment is up, due the last day of classes, Thursday 13 May, at 4:30 p.m. EDT (time corrected 9 May).

• (5 May) Lecture 25 is up. I'll try to post the HW#8 assignment (due 13 May 2004) by tonight.

• (4 May) I've gotten a lot of good questions on HW#7, which I'll put on the Q&A page as soon as I can. In the meantime I've made some clarifying remarks on the HW#7 assignment page. The only real "correction" as such is that I closed the dangling right parenthesis in Question 5, so that you must prove the result for all the NCⁱ, ACⁱ, and ThCⁱ classes except for NC⁰.

• (2 May) Tomorrow's Lecture 24 is up.

• (1 May) I have posted the first two questions and answers on HW#7. I'll add more as they arrive.

• (30 Apr) I have a conflict for most or all of my office hours tomorrow (Friday) at 2:30-3:30. I will be around for most or all of the morning (9-12) and would be happy to discuss the homework then.

• (28 Apr) Lecture 23 and the HW#7 assignment are now up. Sorry the lecture wasn't available sooner.

• (25 Apr) Lecture 22 is now really up. Several questions and answers on HW#6 are now up as well.

• (22 Apr) Lecture 21 is up. The reference to Lecture 22 here earlier was a mistake. I also corrected another typo on HW#6, "MEMBER-MP" where I meant "MEMBER-NP". (Thanks to a different student for spotting this one.)

• (21 Apr) I've corrected a mistake on Question #4 of HW#6. The Lecture 21 notes will be ready later tonight -- in the meantime you may look at the similar Lecture 20 notes from last year.

• (19 Apr) The HW#6 assignment and the Lecture 20 notes are now available. Note that this week our two lectures are on Wednesday and Thursday, as Thu 22 April is a Monday schedule at UMass. The homework index page and the lecture index page now have links to the remainder of the hw's and lectures for the term, and thus include the due dates of the hw's and the titles of the lectures. I'll continue to let you know here when the pages become available.

• (13 Apr) Lecture 19 is now up.

• (13 Apr) I now have some questions and answers on HW#5.

• (11 Apr) Lecture 18, for tomorrow, is now available. Sorry I didn't get this up more in advance of the lecture. If you want an idea of what is going to be presented in advance of my notes, look at last year's notes. For the rest of the term Lecture #n of this year will be pretty close to Lecture #n-1 of last year.

• (11 Apr) It's been pointed out to me that I've now given two different weightings of the midterm and final, 25/40 and 30/35. The only fair thing to do is to give each of you whichever weighting turns out to be better for you, so that's what I'll do.

• (6 Apr) The HW#5 assignment is now up, due a week from Friday, 16 April 2004.

• (6 Apr) Sorry that I have been behind in lecture notes and in posting the HW#5 assignment -- I have just put up Lecture 17.

• (6 Apr) I have graded the on-campus midterms and will return them before class tomorrow morning. I set the scale at 90 for the middle of the A range and 60 for the middle of the B range. Scores were:

  • A range (81-95): 12 students, high was 97

  • AB range (66-80): 13 students

  • B range (51-65): 12 students

  • below B (0-50): two students, each of whom should talk to me

  Students in the B range still have a good chance of an AB in the course if their homework is strong. This exam is 25% of the grade, the final is 40%, and the best seven of eight hw's are 5% each.

• (3 Apr) I am back from Germany and ready to start grading your exams. (I may finish this by Monday.) Thanks to Prof. Immerman for covering last Wednesday's lecture. His notes were somewhat different from the ones I posted before I left. The last several slides on those notes are material that he didn't get to, so they are repeated on the Lecture 16 notes.

• (24 Mar) I've just posted several questions and answers on HW#4.

• (24 Mar) As I mentioned in lecture, I'll be in Germany all next week, though I will have access to email. The TA's will proctor the in-class exam on Monday, and Prof. Immerman will give the lecture on Wednesday.

• (22 Mar) Notes for Lecture 14 are now up.

• (22 Mar) There is a pickup box for CMPSCI 601 in the main department office, in a gray filing cabinet to the left of Pauline's desk as you go in. It has graded homework not picked up in class, and also hardcopy homework solutions. Half the HW#3 solutions were made available in class today, and the other half will go into the folder soon. The graders will try hard to have HW#4 solutions there before the end of the day Friday.

• (22 Mar) The HW#2 performance from on-campus students was strong. There were 19 results in the 100's (because of the extra credit), 11 in the 90's, three in the 80's, four in the 70's, and one in the 50's.

• (22 Mar) As I mentioned in lecture today, I have written three CMPSCI 601 midterms in the last year, for the Spring 2003, Summer 2003, and Fall 2003 terms. The summer and fall exams are probably easier than the spring one, which is the best model for your upcoming midterm.

• (17 Mar) I'll be out of town and unreachable Friday, Saturday, and Sunday (19-21 March).

• (17 Mar) I have now posted Lecture 13, the start of a short unit on first-order logic. Lectures 14, 15, and 16 will follow [BE] fairly closely as we prove soundness (18.3) and completeness (Chapter 19) of the full Fitch proof system for FOL.

  The exam will probably have a question about FOL for Tarski's world like the one from last year's exam. There may also be questions about Lectures 13 and 14.

• (12 Mar) I have just posted HW #4, due for on-campus students a week from Friday. Forty of the 100 points are questions on Lectures 11 and 12, and sixty are problems from [BE]. Most of the latter can be done before Lectures 13 and 14 if you want to work on them over break.

• (12 Mar) The midterm will be in class on Mon 29 March. Here is my midterm from Spring 2003 and solutions for it. This term's midterm will be fairly similar to this, covering Lectures 1-14.

• (9 Mar) I have just posted several more questions and answers about HW#3 on the q&a page.

• (9 Mar) The Jeffrey Amherst Bookstore inform me that they will return their unsold copies of the textbooks for this course during the next week or two. They have copies of [BE], Papadimitriou, and Sipser on the shelf now.

• (9 Mar) I am delaying the off-campus due date for HW#3 until Mon 22 March at 2:00 p.m. EST. HW#4 will be posted soon and due for on-campus students after spring break, Fri 26 March, also at 2:00 p.m. EST. I'll make solutions available by hard-copy to on-campus students at that time, but we clearly won't grade HW#4 before the midterm which is in class Mon 29 March at 10:35 a.m. EST.

• (8 Mar) Notes for Lecture 12, the last lecture before spring break, are now up.

• (5 Mar) There are now some questions and answers on HW#3 posted. Question 6 on HW#3 may be easier after Lecture 11, which has an example of a proof about all Bloop-computable functions.

• (5 Mar) I have now posted Lecture 11, for next Monday. Lecture 12 will follow later today or over the weekend.

• (3 Mar) Graded HW#1 for on-campus students was returned today. If you have questions about the grading, please contant Alex (adingle@cs, Thu 2:30-3:30) about questions 1-4 and Stephen (shart@cs, Wed 1-2) about 5-8. TA office hours are in LGRT 220, near the EdLab.

  The average score was 73, with one 100+, four 90-99, ten 80-89, four 70-79, twelve 60-69, four 50-59, and two under 50. The middle of the A range will be about 85-90 and the middle of the AB range about 65-70.

• (1 Mar) I have just put up Lecture 10 and Homework #3. The latter is due 10 March, a week from Wednesday. I tried to make it shorter than the first two.

• (26 Feb) Lecture 9 is now up. I may be delayed in preparing Lecture 10 -- if you would like to read ahead I can tell you that it will be similar to last year's Lecture 7.

• (22 Feb) I now have some questions and answers on HW#2, and I will add to this page as more come in.

• (22 Feb) Lecture 8 is now up. Hard copies of the rest of the HW#1 solutions should be available in class tomorrow.

• (21 Feb) I have replaced the last question on Homework #2, so please download it again if you have only have the old version. This question depends on the material of Lecture 8, so I doubt anyone has started on it. I'll announce this in class on Monday as well.

• (21 Feb) Lecture 7, for Monday 23 February, is now up. Lecture 8 will follow today or tomorrow.

• (17 Feb) I've just posted the HW#2 assignment, which is 80% from [BE] dealing with the material of Lectures 5 and 6. The other 20% deal with Lectures 7 and 8.

• (17 Feb) There are several more questions answered about HW#1 here. A reminder that HW is due on paper and in class. We'll probably hand out hardcopy solutions after the class -- we can't put solutions on the web because the off-campus students have another week to do HW#1.

• (15 Feb) I have posted Lecture 6, for this coming Wednesday. The HW#2 assignment, which will be partly from [BE], will be posted before Wednesday. The Lecture Notes Directory page now has the tentative titles of the lectures up to spring break.

• (9 Feb) I have finally set office hours for me and for the TA's:

  • Dave: Tuesdays 9-11:30, Friday 2:30-3:30 in room 210 CMPSCI

  • Stephen Hart: Wednesdays 1-2, location TBA

  • Alex Dingle: Thursdays 2:30-3:30, location TBA

• (9 Feb) If you want to test the homework submission functions of the [BE] software, use Alex' email address adingle@cs.umass.edu. He will be taking submissions for HW#2.

• (8 Feb) Lecture 5, for this coming Wednesday, is now posted. Remember that Monday 16 February is a holiday, so that Lecture 6 will be on Wednesday 18 February.

• (6 Feb) Both Lectures 5 and 6 will deal with propositional logic: 5 with its syntax and semantics and with the rules of the Fitch proof system, and 6 with the soundness and completeness of propositional Fitch and a few related topics. I've not forgotten that I owe you a syllabus as well.

• (5 Feb) Lecture 4 is now posted. Lecture 5 should follow fairly soon. The latter will deal with chapters 1-8 and 17 of [BE], so you should read these and determine how much of the material (on propositional logic) is review for you.

• (1 Feb) The first student question on HW#1, and my answer, are now posted here. Pretty good football game, eh?

• (30 Jan) Lecture 3 is now posted,

• (29 Jan) Lecture 2 is now posted, I hope to post Lecture 3 tonight or tomorrow. If this is new material for you, you will want to look at Sipser, chapter 1, or another reference on finite automata.

• (28 Jan) It turned out that the snow was less than expected and we had class as scheduled. I'll let you know when Lectures 2 and 3 are posted -- they will be similar to lectures 1 and 2 from Spring 2003.

• (27 Jan) The HW#1 assignment is now posted, due three weeks from tomorrow. Many questions deal with the models of computation defined in Lecture 1, and the later ones deal with Lectures 2-4.

• (27 Jan) There is serious snow forecast for tomorrow's opening class. I will hold class if and only if the University is open by 10:35 -- check this page for the latest. In particular, if UMass opens at 11:00 there will be no class.

• (26 Jan) I have just posted Lecture 1. In general I will try to get notes posted a day or two before each lecture is delivered. I hope to get HW#1 posted later today.

• (21 Jan) I am just starting construction of the site for the new offering of the course today. In most respects the course will follow the model of the Spring 2003 version, whose web page is here.

  The most important change is in the textbook. The only required text is Barwise and Etchemendy, Language, Proof, and Logic (University of Chicago Press, 2002). (I have ordered copies of this at the Jeffrey Amherst College Bookstore.) Some of the homework (starting with HW#2 rather than HW#4 as last year) will be graded electronically by the website for this book. You will thus need a new copy, unless you bought the book before for a different course.

  The Papadimitriou text, Computational Complexity (Addison-Wesley, 1994), is now recommended rather than required. We will largely use this book's notation in lecture, but the primary text will be the lecture notes available on-line.

  Sipser's Introduction to the Theory of Computation (PWS, 1997) is also a useful reference, particularly on the basic formal language material that you might or might not have seen in an earlier course.

Last modified 14 May 2004