CS154Spring 2013Sec1Home Page/Syllabus

Formal Languages and Computability

This course covers the basics of finite automata, context-free languages, Turing machines, computability. Finite automata are used in the lexical analysis part of a compiler, and are also used for string matching, and for simple AIs in video games. Context-free languages are used for parsing in compilers. XML is a currently trendy language for defining essentially context-free languages. Computability is the study of what it is possibility to get a computer to do. In computability theory, we use an abstract model of a computer called a Turing Machine and study what it can and cannot do. By the end of this course, you should be able to: (1) Write a grammar for a language described otherwise. (2) Construct deterministic and non-deterministic machines for various languages. (3) Describe a language in terms of a regular expression. (4) Find a regular expression for a language described by a finite automaton and conversely. (5) Construct a deterministic finite automaton from a non-deterministic one. (6) Minimize a deterministic automaton. (7) Be able to use a pumping lemma to show that some languages are not regular and/or not context-free. Use closure properties to simplify proofs of non-regularity of languages. (8) Be able to construct a pushdown automaton accepting a given language. (9) Construct a Turing machine accepting some simple languages. (10) State in precise mathematical terms what is meant by undecidability of the Halting Problem, and be able to show the undecidability of simple extensions of the Halting Problem, using the reduction technique.

Below is a tentative time table for when we'll do things this quarter:

Grades will be calculated in the following manner: The person or persons with the highest aggregate score will receive an A+. A score of 55 will be the cut-off for a C-. The region between this high and low score will be divided into eight equal-sized regions. From the top region to the low region, a score falling within a region receives the grade: A, A-, B+, B, B-, C+, C, C-. If the boundary between an A and an A- is 85, then the score 85 counts as an A-. Scores below 55 but above 50 receive the grade D. Those below 50 receive the grade F.

If you do better than an A- in this class and want me to write you a letter of recommendation, I will generally be willing provided you ask me within two years of taking my course. Be advised that I write better letters if I know you to some degree.

This semester we will have four homeworks and weekly quizzes. Every Monday this semester, except the first day of class, the Midterm Review Days, and holidays, there will be a quiz on the previous week's material. The answer to the quiz will either be multiple choice, true-false, or a simple numeric answer that does not require a calculator. Each quiz is worth a maximum of 1pt with no partial credit being given. Out of the total of eleven quizzes this semester, I will keep your ten best scores.

As part of your homework score, every Wednesday this semester, except the first day of class, the Midterm Review Days, and holidays, there will be two to four problems which are due in class. Your solution should be handwritten (not typed unless you give me a reason from the DRC). Your answer does not have to be verbose, but should be in complete sentences, should set up the problem, and should explain how you solved it. From these four problem, I will select two for grading. We will go over the solution to these two problems in class on the due date. If you cannot attend on a given Wednesday, make sure someone turns in your homework for you. Each problem that is graded will contribute up to 1 point to the next homework score. These problems will be graded on a scale: 1 - completely correct; 0.5 - mainly correct, but having defects in logic, clarity, or grammar; 0 - didn't do, or was mainly incorrect.

Links to the current list of homeworks and quizzes can be found on the left hand frame of the class homepage. After an assignment has been returned, a link to its solution (based on the best student solutions) will be placed off the assignment page. Material from assignments may appear on midterms and finals. Homeworks for this class should be your own individual work.

In addition to the handwritten problem, there may be JFLAP and simple coding exercises in Java that are due on the homework due date. These will be submitted and returned completely electronically. To submit an assignment click on the submit homework link for your section on the left hand side of the homepage and filling out the on-line form. Hardcopies or e-mail versions of your assignments will be rejected and not receive credit. Homeworks will always be due by the start of class on the day their due. Late homeworks will not be accepted and missed quizzes cannot be made up; however, your l owest score amongst the four homeworks and your quiz total will be dropped.

When doing the programming part of an assignment please make sure to adhere to the specification given as closely as possible. Names of files should be as given, etc. Failure to follow the specification may result in your homework not being graded and you receiving a zero for your work.

The midterms will be during class time on: Feb 20 and Apr 10.

The final will be: 12:15-2:30pm, Tuesday, May 21 (Sec 1), 5:15-7:30pm, Monday, May 20 (Sec 3).

All exams are closed book, closed notes and in this classroom. You will be allowed only the test and your pen or pencil on your desk during these exams. The final will cover material from the whole quarter although there will be an emphasis on material after the last midterm. No make ups will be given. The final exam may be scaled to replace a midterm grade if it was missed under provably legitimate circumstances. These exams will test whether or not you have mastered the material both presented in class or assigned as homework during the quarter. My exams usually consist of a series of essay style questions. I try to avoid making tricky problems. The week before each exam I will give out a list of problems representative of the level of difficulty of problems the student will be expected to answer on the exam. Any disputes concerning grades on exams should be directed to me, Professor Pollett.

It is often the case that students score below 50% on the midterms and final for this class. For the midterm, I will give you a chance to redeem half of the points that you miss. To get these points you need to study what you got wrong on a midterm and then come to my office. I will choose one problem from amongst those you got wrong to ask questions about. My questions may or may not be more involved than the actual midterm problem. I will also hold you to a stricter standard for your answers. If you answer my questions to my satisfaction, I will give half of the marks you missed on the midterm back.

If you believe an error was made in the grading of your program or exam, you may request in person a regrade from me, Professor Pollett, during my office hours. I do not accept e-mail requests for regrades. A request for a regrade must be made no more than a week after the homework or a midterm is returned. If you cannot find me before the end of the semester and you would like to request a regrade of your final, you may see me in person at the start of the immediately following semester.

The campus policy to ensure compliance with the Americans with Disabilities Act is:
"If you need course adaptations or accommodations because of a disability, or if you need special arrangements in case the building must be evacuated, please make an appointment with me as soon as possible, or see me during office hours. Presidential Directive 97-03 requires that students with disabilities register with DRC to establish a record of their disability."

The university policy regarding credit hours for classes states:
Success in this course is based on the expectation that students will spend, for each unit of credit, a minimum of forty-five hours over the length of the course (normally 3 hours per unit per week with 1 of the hours used for lecture) for instruction or preparation/studying or course related activities including but not limited to internships, labs, clinical practica. Other course structures will have equivalent workload expectations as described in the syllabus.

More information about SJSU policies and procedures can be found at the following links: