Com S 531
Announcement Archives


  • January 20, 1999
    As there are a few openings in the class, students who are not registered but wish to add this course should contact Dr. Chaudhuri by Monday.
  • January 23, 1999
    Students who have not updated their records with their new social security numbers wil need to do so with the SSG. This will ensure that they are automatically included in the mailing lists of Computer Science courses (including CS531).
  • January 23, 1999
    Homework 1 has been posted.
  • January 27, 1999
    If you have not received the test e-mail sent out on monday, please send e-mail to the course account ( ) to be included on the list.
  • January 29, 1999
    Homework 2 has been posted.
  • February 4, 1999
    Homework 3 has been posted.
  • February 5, 1999
    There is an error in the statement of HW 2 Problem 4. You may not be able to come up with an NFA with exactly m^3 states. You can come up with your NFA in one of two ways:
    (1) use m^3 + 1 states
    (2) you can have a set of start states instead of a unique start state.
    Sorry about the confusion!
  • February 8, 1999
    Correction in HW3:
    In the problem statement of Q.1 ( 1.23(d)) replace {0,1} by {0,1}*.
    So now the new problem statement is {w|w (element of) {0,1}* is not a palindrome }
  • February 10, 1999
    Soma's office hours will be 11-12 instead of 10-11 today. Sorry about the short notice but it could not be helped.
  • February 11, 1999
    If you still have'nt received any mail from the cs531 mailing list, please send a mail to the cs531 account immediately.
  • February 12, 1999
    HW4 has been posted.
  • February 15, 1999
    Problem 2.2 (a) should read Example 2.20 instead of 2.21.
  • February 16, 1999
    • A sample exam from Fall 96 has been posted on the Exam Information page.
    • Please send e-mail to the course account on your preference for the timing of the exam.
    • No solutions will be posted for homeworks that are returned. Please read the note in the Homeworks page.
  • February 17, 1999
    The syllabus for exam 1 has been posted on the Exam information page.
  • February 19, 1999
    Exam 1 will be held at 7-9 PM in Durham 171.
  • February 19, 1999
    The library has been told to place the suggested texts on reserve. If you do not find them there yet, you may see Soma at her office to borrow the departmental copies.
  • February 22, 1999
    Solutions and hints for HW 4 have been posted on the homeworks page.
  • February 23, 1999
    Problem 5 (b) in the sample exam is wrong. As we showed in class, the language can be shown to be non-regular using the pumping lemma. The string to use is a b^n c^n.
  • February 26, 1999
    HW5 has been posted.
  • March 2, 1999
    Click here for information on who graded what in Exam 1
    The current grades are posted. Follow the link below.
    New: HW 6 has been posted.
  • March 12, 1999
    HW 7 has been posted.
  • March 24, 1999
    1) In Q.1 of HW 7, to provide a counter-example, you must first show that the language you choose is context-free by giving a grammar. Then prove that the language obtained by applying the operator NOEXTEND (or INVERSE) is not context-free.
    2) In Problems 3.9, 3.11 and 3.13, we would like to see proofs of your answers.
    3) Please mention the references you use in solving the homeworks.
  • March 25, 1999
    Homework 8 has been posted.
  • March 26, 1999
    Updated grades have been posted. An error in the calculation of the weight of Exam 1 has been rectified. The weight should be 25 instead of 20.
  • April 6, 1999
    Since Exam. 2 is on Wednesday, we are moving the Thursday office hours for this week as follows (note that there will be no office hours this Thursday):
    Vikram - Tuesday (4/6) 3:00 - 4:30 p.m.
    Sridhar - Wednesday (4/7) 3:30 - 5:00 p.m.
    The exam syllabus, time and place have been posted on the Exam Information page.
  • April 6, 1999
    Soma will have to miss her office hours at 10am tomorrow for an urgent meeting. She will instead see anyone between 1 and 3 today.
  • April 8, 1999
    Homework 9 has been posted on the Homeworks page.
  • April 16, 1999
    The updated grades have been posted on the Current Grades page. If you find any discrepancy in your grade, please bring it to the notice of a TA immediately.
  • April 16, 1999
    Homework 10 has been posted. It is due April 23.
  • April 19, 1999
    Click here for information on who graded what in Exam 2
  • April 24, 1999
    I am sorry I was unable to put Homework 11 up by Friday. It will be put up first thing Monday. I'll make it shorter than usual, but if it is still a problem, let me know. Remember that we will use your ten best homeworks, so you don't need to do the last one.
  • April 26, 1999
    Homework 11 has been posted. I will ask the TAs to give extra help if you decide to do this, since it was posted late. I will be happy to help you out with it too.
  • April 28, 1999
    Homework 9 will be returned by Friday, April 30. We expect to return homework 10 and post the solutions for HW 11 by next Tuesday, May 4. Also, we will let you know of the office hours schedule for the finals week soon.
  • May 4, 1999
    The solutions/hints for HW 11 have been posted on the Homeworks page.
  • May 6,1999
    The CS 531 Exam will be held in CARVER 001(basement) from 9:45-11:45 a.m on Friday, May 7. Please note the CHANGE in location from the regular lecture meeting place.
  • May 10,1999
    The Final Grades have been posted. The Final Exam. was graded out of 135 instead of 150. Enjoy your Summer Vacations.
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    This page was last modified on February 15, 1999.