CS243 Fall 2012

    Welcome to the home page for
    Computer Science 243 -
    Discrete Structures!

Logistical Information:

Instructor: Işıl Dillig
Time: Tuesday, Thursday 2:00 pm - 3:20 pm
Place: McGlothlin-Street (MCGL) Hall 20
Instructor e-mail: idillig@cs.wm.edu
Instructor office hours: Tuesday 3:20 pm - 5:20 pm; Thursday 3:20 pm-4:20 pm in MCGL 111
TA: Weilin Wang
TA's e-mail: wwang01@email.wm.edu
TA's office hours: Monday 4-6 PM, Tuesday 9-10 AM in MCGL 139
Prerequisite: CS 141 -- Computational Problem Solving
Textbook: Kenneth H. Rosen, Discrete Mathematics and Its Applications, 6th edition, McGraw Hill, 2007
Course Webpage: http://www.cs.wm.edu/~idillig/cs243/

Course Description:

This course covers elementary discrete mathematics for computer science. It emphasizes mathematical definitions and proofs as well as applicable methods. Topics include propositional logic, first-order logic, proof methods; sets, functions, relations; mathematical induction, recursion, well-ordering; elementary graph theory; permutations and combinations, counting principles; discrete probability. Please refer to the syllabus for a more detailed description.

Requirements and Grading:

  • This course has two midterms. Each midterm will be an in-class and closed-book, closed-notes exam. Each midterm counts for 20% of your final grade.
  • The course has a closed-book, closed-notes final exam. The final exam counts for 40% of your grade.
  • There will be weekly written homework assignments. These assignments do not involve any programming, and will help you better understand the material taught in the class as well as prepare you for the midterm and final exams. The homework assignments collectively count for 20% of your final grade.
  • There may be a curve of the final grades, although the lower bounds of the standard scale are guaranteed, i.e., you will get an A- or A if your grade is 90 or above, a B(-/+) if it is 80-89, etc.

    Homework Policies:

  • Each assignment is due at the beginning of class on the indicated date.
  • Each homework should be done in accordance with the Honor Code .
  • Homework assignments should be typeset in LaTeX. You must pick-up LaTeX skills by yourself. However, to make things a little easier for you, Prof. W. Mao has written a brief introduction, called LaTeX summary, that contains a minimum set of things you need to know to produce a homework write-up in LaTeX. Moreover, each homework assignment will be posted both in PDF and in the source LaTeX.
  • Homework write-ups must contain for each problem both the problem description and its solution.
  • The lowest homework score will be dropped when calculating final grade.


  • This first class will meet on Thursday August 30 at 2:00 pm in MCGL 020.
  • Weilin will be holding a lab session to teach Latex on Monday 09/03 in James Blair 205 from 6 to 7 PM
  • For those of you who could not attend the Latex session on Monday 09/03, here are the examples covered during the session:
  • Sample solutions for the first midterm are available here.
  • Sample solutions for the second midterm are available here.

    Honor Code:

  • For the homework assignments you may talk about the problem with fellow students, the TA, and the instructor, but the write-up must be yours. In particular, when discussing with fellow students you must strictly follow the "empty hand policy": You cannot leave a discussion meeting with any record of the discussion (hard copy or electronic). All scratch paper must be torn and thrown away, and boards erased. In your homework write-ups, you should also give credit to your collaborators for each problem. Finally, you may neither consult students that have taken the course previously, nor their completed work.
  • For the written assignments and the projects, you are allowed to consult other books, papers, or published material. The Web is also considered a publication media. However, you MUST reference all the sources that helped you in the assignment.
  • You should not plagiarize. Therefore, you should write solutions in your own words, even if the solutions exist in a publication that you reference.


    Date Lecture topics Slides Reading Assigned Due
    08/30 Propositional Logic Lecture 1 Rosen 1.1 (p. 1-16)    
    09/04 Satisfiability, validity Lecture 2 Rosen 1.2 (p. 21-30) Homework 1
    (Latex source)
    09/06 First Order Logic Lecture 3 Rosen 1.3, 1.4    
    09/11 Logical Inference Rules Lecture 4 Rosen 1.5 Homework 2
    (Latex source)
    Homework 1
    09/13 Proof Methods Lecture 5 Rosen 1.6, 1.7    
    09/18 Sets Lecture 6 Rosen 2.1, 2.2 Homework 3
    (Latex source)
    Homework 2
    09/20 Functions Lecture 7 Rosen 2.3    
    09/25 Sequences, summations Lecture 8 Rosen 2.4   Homework 3
    09/27 Midterm I review        
    10/02 MIDTERM I        
    10/04 Number theory I Lecture 9 Rosen 3.4, 3.5    
    10/09 Number Theory II Lecture 10 Rosen 3.6, 3.7 Homework 4
    (Latex source)
    10/11 Mathematical induction Lecture 11 Rosen 4.1    
    10/16 FALL BREAK        
    10/18 Class canceled        
    10/23 Strong induction, recursion Lecture 12 Rosen 4.2 Homework 5
    (Latex source)
    Homework 4
    10/25 Structural Induction Lecture 13 Rosen 4.3  
    10/30 Intro to counting Lecture 14 Rosen 5.1, 5.2    
    11/01 Permuations, combinations Lecture 15 Rosen 5.3   Homework 5
    11/06 Midterm II review        
    11/08 MIDTERM II      
    11/13 Solve midterm 2        
    11/15 Permutations, combinations Lecture 16 Rosen 5.4, 5.5 Homework 6
    (Latex source)
    11/20 No lecture        
    11/22 THANKSGIVING        
    11/27 Probability Lecture 17 Rosen 6.1, 6.2   Homework 6
    11/29 Probability Lecture 18 Rosen 6.3, 6.4 Homework 7
    (Latex source)
    12/04 Final Review Lecture 19      
    12/06 Final Review