ITEC 420 - Computability Theory and Formal Languages
Fall 2019


Weekly Notes Topics Reading Assignments
Week 1 Chapters 1 and 2, App A HW1a ready for fall 19
HW1b ready for fall 19
Week 2
  • PPTs on Chapter 2: Strings and Languages (we will use strings and languages all semester!)
  • PPTs on Chapter 4: FSM and Regular Languages (PPTs under revision)

  • News, Announcements, Discussion:
    • Homework: Due by 4
      • HW 1b Due by 4. Bring it by the office.
      • HW2 will be up soon (if you want to look at it before class)
      • Keep your graded work and verify your grade (of course)
    • ATRL:
      • Keep lab looking nice
      • Keep environment professional
      • Respect the space and respect the rules
      • Employers in there almost every day
      • Faculty know who responsible students are and nominate them
    • Sys Admin Matt Gardner (smiling and sleepy?): New arrival!

  • Notes from previous semesters:

  • This is the only week that homework will be due every class day.
Chapter 2 HW1a ready for fall 19
HW1bready for fall 19
HW1c ready for fall 19

HW2 ready for fall 19
Week 3 Chapters 1, 3, 5 HW2 for fall '19

HW3a for fall '19
HW3b for fall '19
Week 4
  • Chapter 5: More Finite State Machines
  • Chapter 6: Start Regular Expressions

  • The bear on VT campus
Chapter 5 HW3a for fall '19
HW3b for fall '19

HW4a for fall '19
HW4b for fall '19
Week 5
  • Chapter 6: More Regular Expressions
  • Exam Monday of next week: 09/30/10
    • Topics (updated for fall 2019)
    • Review Session: Sunday at 2:00 in DA 212.

  • Notes from previous semesters:

  • My weekend: No black bears, but a white one?!
    • C'burg street fair: It's more blessed to give than to receive
    • News Flash: RU CS alum inducted into VT Sports Hall of Fame
    • What's the difference:
      • ... the concatenation of languages L1 and L2 (ie L1 L2)
      • ... the concatenation of languages L1 and L2 (eg L1 L2)
      • id est vs exempli gratia (use periods?)
Chapters 5 and 6 HW4a for fall '19
HW4b for fall '19

HW5 is HW5 for fall '19
coming soon
Week 6
  • Exam Monday of THIS week: 09/30/10
    • Topics (updated for fall 2019)
    • Review Session: Sunday at 2:00 in DA 212.

  • Chapter 6: Finish Regular Expressions (prove every FSM has equivalent RE)
    • Ripping states

  • Chapter 8: Pumping Theorem and Closure Properties (SKIPPED)
  • Chapter 10: Brief summary of RL, FSM, RE (we skip, but useful)

  • Regular Grammars [Chapter 7]
    • Would you like to take a stroll through a FA?
  • Other things:
    • 320 - Referential transparency
    •          glob: Integer := 0;
               function f(i: integer) is
               begin
                  glob := glob + 1;
                  return glob
               end f;
               ...
               put(f(3));
               put(f(3));
               -- Is math like this?
                     
    • 320 - Functions have type (set of values/operations). What are their operations?
    • Sunday review: What did you think?
    • Tabula Rasa and Castor Oil
    • Dallas trial - person-to-person (like teaching)
    • In honor of a founder of the CS Department (1983, not 1989; friends of all ages)
    • Moon flowers
    • Spring 20 schedule!

  • Chapter 11: Context Free Grammars and Context Free Languages (CFG and CFL)

  • Notes from previous semesters:
Chapters 6, 8, and 10 HW5a for fall '19
HW5b for fall '19
HW5c for fall '19
Week 7

  • Chapter 7: Regular Grammars (Strolling through a FSM!)
  • Chapter 11: Context Free Grammars and Context Free Languages (CFG and CFL)

  • Friday: Fall break!!
Chapters 7 and 11
Week 8
  • Long weekend:
    • Nicaragua housing
    • Indian Valley, Floyd County, Youth
    • Car HVAC, TV Speaker, First job advice
  • More other:
    • Homework
    • Raaaaiiiinnnn
    • 352?? Demo
    • 460
    • Survey results
    • Hookey, and CS at the pulmonologist
      • OED: Dictionary of Americanisms (1848). Mark Twain - The Story of the Bad Little Boy (c 1865).
      • Also: Hooky, hookie
    • What do these have in common: Armadillo shells, the 4th of July, "revolution in the air", BHS Soccer, green hair, rolling suitcase, CSAT Dean's Scholar, loud CS prof, 380?
  • Pumping Lemma for Regular Languages:
    • Pigeonhole principle: n holes, n+1 pigeons means some hole has >1 pigeon
    • Pumping lemma: Long strings in a regular language can be pumped (up or down) because computation must go through a loop
    • Consequence: If a long string cannot be pumped, then the language is not regular
  • Finish grammars: Finish expression grammar. CFG and CSG. Grammar and language hierarchy
    • CS but Not CF: anbncn, ambnambn and ww
  • Chomsky: Chomsky Normal Form and Chomsky's Hierarchy
    • Any grammar can be transformed to CNF.
    • For CNF grammar: Length of derivation for w = 2*|w|-1 .
  • PDA for anbn: Push the a's, then pop them on the b's
  • Chapter 11: Context Free Grammars and Context Free Languages (CFG and CFL)

  • Notes from previous semesters:
  • Chapter 2
    Week 9  
    Week 10 Chapter 2
    Week 11 Chapters 17
    • Exam 2 this week:
      Monday 11/4/19

    • HW8a is ready here Due MON 11/11/19
    • HW8b is ready here Due FRI 11/17/17
    Week 12  
    • HW8c is ready here Due FRI 11/17/17

    • HW9a is ready here Due ??? 11/??/17
    Week 13  
    • HW 11 is ready! Due Friday Wednesday after break, 12/04/13 12/06/13
    Week 14 Happy Thanksgiving!!  
    • HW10 is ready here
    Week 15  
    Week 16   Comprehensive
    Final Exam
    Notes for entire semester