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COMS W3261
Computer Science Theory
Fall 2009
 Announcements
  Class meets 1:10-2:25pm, Mondays and Wednesdays, 702 Hamilton Hall.
Midterm 2 will be in class, 1:10-2:25pm, Wednesday, November 11, 2009.
Class bulletin board: https://courseworks.columbia.edu
 Teaching Staff
 Name   email   Office hours    Location 
Prof. Al Aho   aho@cs.columbia.edu   Mon & Wed 2:45-3:45   513 CSB
 
Sumeet Jindal   sj2405@columbia.edu   Mon & Fri 10:00-11:00   TA Room, 122 Mudd
Injung Kim   ik2249@columbia.edu   Wed 3:00-4:00 & Thu 1:00-2:00      TA Room, 122 Mudd
Liang Zhang   lz2232@columbia.edu   Mon & Wed 9:45-10:45      TA Room, 122A Mudd
 
 Course Overview
  In Computer Science Theory you will discover the fundamental models of computation that underly computer hardware, software, and programming languages, and the limits to what problems computers can solve.

The course will cover the important formal languages in the Chomsky hierarchy -- regular sets, context-free languages, and recursively enumerable sets -- as well as the formalisms that generate these languages and the machines that recognize them. The course will also introduce the basic concepts of computability and complexity theory by focusing on the question, "What are the fundamental capabilities and limitations of computers?"

The concepts covered in this course will be amply illustrated by applications to modern hardware design, software design, and natural language processing.
 Pre- or Corequisites
  COMS W3137 Data Structures and Algorithms
  COMS W3203 Discrete Mathematics
 Schedule 2009
Date  Lecture  Reading 
Sep 9   Introduction to CS Theory  HMU, Ch. 1  
Sep 14   Regular Expressions   HMU, Sect. 3.1  
Sep 16   Deterministic Finite Automata   HMU, Sects. 2.1-2.2  
Sep 21   Nondeterministic Finite Automata   HMU, Sects. 2.3-2.4  
Sep 23   NFAs with Epsilon-Transitions   HMU, Sects. 2.5-2.8 
Sep 28   Constructing a Regular Expression from a DFA   HMU, Sects. 3.1-3.3  
Sep 30   Regular Expressions to NFA's   HMU, Sects. 3.2-3.7, 4.1  
Oct 5   Properties of Regular Languages   HMU, Sects. 1.1-4.2  
Oct 7   Solutions to Midterm 1    
Oct 12   Equivalence and Minimization of DFAs   HMU, Sects. 4.3-4.7  
Oct 14   Context-Free Grammars   HMU, Sects. 5.1-5.6  
Oct 19   Pushdown Automata   HMU, Sects. 6.1-6.2 
Oct 21   PDA's and CFG's   HMU, Sects. 6.3-6.7  
Oct 26   Normal Forms for CFG's   HMU, Sect. 7.1 
Oct 28   Pumping Lemma and Closure Properties for CFL's   HMU, Sects. 7.2-7.3  
Nov 4   Decision Properties of CFL's   HMU, Sects. 7.4-7.7 
Nov 9   Sample Midterm 2    
 Required Text
  John E. Hopcroft, Rajeev Motwani, and Jeffrey D. Ullman
Introduction to Automata Theory, Languages, and Computation, Third Edition
Pearson/Addison-Wesley, 2007, ISBN 0-321-45536-3
 Additional References
  Michael Sipser
Introduction to the Theory of Computation, Second Edition
Thomson, 2006
  Alfred V. Aho and Jeffrey D. Ullman
Foundations of Computer Science, C Edition
W. H. Freeman, 1995
An online version of this book is available here.
 Class Policies
  Grading 30 % First midterm
30 % Second midterm
40 % Final
aho@cs.columbia.edu Updated June 29, 2009