CS CS 311 - Computational Structures - Fall Term 2012
CRN:         11043 (Sheard).    14577 (Hook)
Course No.   CS 311
Course Name. Computational Structures (4 cr)
Times:       Tue & Thur 10:00-11:50 (Sheard).   14:00-15:50 (Hook)
Place:       BHB 222 (Sheard).    FAB 40-07 (Hook)
Professor:   Tim Sheard      James Hook
Office:      FAB 120-04 (Sheard).       FAB 120-05   (Hook)
Phone        503-725-2410 (Sheard).    503-725-5540 (Hook)
Office Hrs   Friday 10-12 am (Sheard).    Monday 3-5 pm (Hook).

TA:             Long Mai
Email:          mai.t.long88@gmail.com
Office hours: Wednesdays 10:00-12:00 Noon, "Fishbowl" Suite 120 FAB


Prerequisites. You should know the material listed in the review. If you don't, you should consider dropping the course. If the material is familiar, you may want to review it my reading the listed material from the textbook by Hein.
Review: Review of Sets
Readings:
        1.1, 1.2                Sets
        1.3.3, 3.1.2, 3.2.2     Strings
        6.1, 6.2, 6.3, 7.1      Logic
        4.4                     Proofs

  1. Tuesday September 25, 2012
    Due Today:
    Announcements:
    Due Today: Self exam on prerequisites (above)
    Class Topic:
            Class preliminaries Textbook, Policies, Syllabus, etc.
            Computation and Languages.
    Assigned today:  Assignment #1. Instruction Decoder. Due: Tuesday October 2.
    Readings: Outline of the course, 4-bit adder as a Mealy machine. Sections 2.1, 2.2, 2.3, and 2.4
    

  2. Thursday September 27, 2012
    Due Today:
    Announcements:
    Class Topic:
            The Big Picture
            Another look at Assignment #1.
            Acceptance by DFA. What it means for a DFA to accept a string
            Constructing proofs by induction.
            More examples of proofs.
    Assigned today:
    Readings:
            Hein 11.2 DFAs
            Hein 11.2.6 Representing and Executing Finite Automata
            Outline Sections  3.1 and 3.2
    

  3. Tuesday October 2, 2012
    Due Today:   Assignment #1. Instruction Decoder is due today.
    Announcments:
    Class Topic:
            Reasoning about DFAs, some simple closure properties.
            Introduction to NFAs, Non-deterministic Finite state Automata.
            NFAs with spontaneous transitions (sometimes called eNFAs)
            NFAs and closure under concatenation and iteration.
    Assigned today:
             Assignment #2. Proofs and DFA constructions. Due Tuesday Oct. 9, 2012.
    Readings:
            Hein 11.4.2 Properties of Regular languages.
            Hein 11.2.2 NFAs
            Outline, Section 4.  Here we go over the closure properties
            using different examples, and we provide proofs that the constructions really do what
            they are supposed to. Please study the proofs, so you can get an idea how to
            prove that two DFAs recognize the same langauge.
    

  4. Thursday October 4, 2012
    Due Today:
    Announcements:
            D2L has been set up for Tim Sheard's class. It contains a gradebook and Discussion forum.
            Sophomores and Juniors are eligible for the Barry Goldwater Scholarship
                    There is an important info meeting about this on Friday, Oct 26, from 10-11am in the University Services Building,
                    room 402. Leena Shrestha is the contact person for the scholarship at PSU. (leens@pdx.edu)
    Class Topic:
            DFAs and NFAs recognize the same class of languages
            Regular Expressions
    Readings:
            Hein 11.3.2 NFAs to DFAs
            Hein 11.3.3 Minimal DFAs
            Hein 11.1.1 and 11.1.2  Regular Expressions
    Assigned today:
    

  5. Tuesday October 9, 2012
    Due Today:
             Assignment #2. Proofs and DFA constructions is due today.
    Announcments:
    Class Topic:
            Quiz #1 is Today. First 15 minutes of class for Sheard Section.
            Minimizing DFAs
            Regular Expressons and Automata are the same
    Readings:
            Hein 11.2.3 RE to NFA (take 1)
            Hein 11.2.4 DFA to RE
            Hein 11.3.3 Minimal DFAs
            Hein 11.3.1 RE to NFA (take 2)
    Assigned today:
             Assignment #3. REs, DFAs, NFAs. Due Tuesday Oct. 16, 2012.
    
    

  6. Thursday October 11, 2012
    Due Today:
    Announcements:
            T.A. Office hours announced: Wednesdays 10:00-12:00 Noon, "Fishbowl" Suite 120 FAB
    Class Topic:
            Direct computation of Acceptance of Regular Expressions
            Quiz #1 is Today. Last 15 minutes of class for Hook Section.
    Assigned today:
    

  7. Tuesday October 16, 2012
    Due Today:
             Assignment #3 is due today.
    Announcments:
    Class Topic:
            Go over quiz (Sheard section).
            Algorithms over Regular Language systems.
            Pumping Lemma.
    Assigned today:
            Homework #4 due in class Tuesday, October 23, 2012
    Readings:
            Hein 1.4.2 Pumping Lemma
    
    

  8. Thursday October 18, 2012
    Due Today:
    Announcements:
            Mid term exam date fixed on Tuesday October 30, 2012
    Class Topic:
            In class pumping-lemma exercises.
            Regular Grammars
    Assigned today:
    Readings:
            Outline Section 7 on regular and non-regular languages.
            Hein 11.4.1 Regular Grammars
    

  9. Tuesday October 23, 2012
    Due Today:
            Homework #4 due today.
    Announcments:
    Class Topic:
            more on Mealy Machines
            Context free grammars
    Assigned today:
            Homework #5 due in class Tuesday, October 30, 2012
    Readings
            Outline Section 8:  Mealy Machines and Parallel Prefix
            Hein 12.1
    
    

  10. Thursday October 25, 2012
    Due Today:
    Announcements:
            Recall exam next Tuesday. Here are some practice exam questions.
    Class Topic:
            Push down automata.
    Assigned today:
    Readings
            Hein 12.2
    

  11. Tuesday October 30, 2012
    Due Today:
            Homework #5 due today.
    Announcments:
    Class Topic:
            Date of Midterm exam
    Assigned today:
    

  12. Thursday November 1, 2012
    Due Today:
    Announcements:
    Class Topic:
            Equivalence of context free grammars and push down automata
            Context Free Expressions (an analog to regular expressions).
    Assigned today:
            Homework #6, Context Free Languages. Due Thursday Nov. 8, 2012.
    Readings:
            Hein 12.2.2 CFG = PDA
    

  13. Tuesday November 6, 2012
    Due Today:
    Announcments:
    Class Topic:
            Go over midterm exam. Statistics for Sheard section here.
            Closure Properties of context free languages and Chomsky Normal form.
            Context Free pumping lemma
    Assigned today:
    Readings:
            Hein 12.4.2, pp. 804-808,  Closure Properties CFL.
    
    

  14. Thursday November 8, 2012
    Due Today:
            Homework #6, Context Free Languages.  Due today.
    Announcements:
    Class Topic:
            Parsing context free grammars.
            Transformation of CF grammars.
            CFL Big Picture.
    Assigned today:
            Homework #7, grammar transformations, CF puming lemma. Due Thursday Nov. 15, 2012.
    Readings
            Hein 12.3 Parsing
    

  15. Tuesday November 13, 2012
    Due Today:
    Announcments:
    Class Topic:
            tentative date of quiz #2
            Turing machines, instantaneous descriptions, acceptance.
    Assigned today:
    Readings:
            Hein 13.1 Turing machines and equivalent models.
    

  16. Thursday November 15, 2012
    Due Today:
            Homework #7 due today.
    Announcements:
            Winter classes to consider
                    Functional Languages
                    Logic via Foundational Algorithms
    Class Topic:
            Primitive recursive functions
            Partial recursive functions
    Readings
            Hein 18.2.3 Primitive and Partial recusive functions
    Assigned today:
            Homework #8 Primitive recusion worksheet. Due Tuesday Nov. 27, 2012.
            You may want to study the file NaturalPR.hs
    

  17. Tuesday November 20, 2012
    Due Today:
    Announcments:
            Todats lecture is a guest lecture by Professor Andrew Black.
    Class Topic:
            Scheme
            Download the Racket system (an industrial "batteries included" Scheme implementation).
    Assigned today:
    

  18. Thursday November 22, 2012
    Thanksgiving Day, No classes
    

  19. Tuesday November 27, 2012
    Due Today:
            Homework #8 due today.
    Announcements:
    Class Topic:
            Finish notes on partial recursive functions
            Self interpreters
                    Hantao Zhang's notes on self interpretation in scheme http://homepage.cs.uiowa.edu/~hzhang/c123/Lecture6.pdf
                    Olivia Danvys Scheme self interpreter http://www.daimi.au.dk/~laumann/dProgSprog/Scheme/self-interpreter.scm
    Readings: Outline Section 11 (Primitve and Partial Recursive functions) and Section 12 (Exploring Computability).
    Assigned today:
            A non graded homework #9 will be assigned today. Material covered here will be fair game for the final exam.
    

  20. Thursday November 29, 2012
    Due Today:
    Announcements:
    Class Topic:
            Discusion of final exam (practice exam here)
            Undecideability
    Assigned today:
            Practice homework #9. Not graded.
    Readings: Outline Section 12 (Exploring Computability).
    
    

  21. Final Exams. Note which one applies to you.
    Tuesday December 4, 2012, 10:15-12:05 (Sheard) Monday December 3, 2012, 10:15-12:05 (Hook)
Three Goals
  1. There are problems computers can't solve.
  2. Most natural problems of interest answer questions about programs.
  3. The class of computable functions is robust under definition (all reasonable models agree).
Back to the class web-page.