CS 1050 A Constructing Proofs

Fall 2008

[Syllabus] [Homework]


 

Topics
Date(s)
Reading
Introduction and Overview :
Significance of Formal Reasoning in All Aspects of Computer Science
Examples of Cases that will be Discussed
Lecture Outline (I)
Tue, Aug 19
-----
Propositional Logic
Lecture Outline (II)
Thu, Aug 21
Reading:
Rosen pp 1-30.
Theory emphasis: pp 1-6,10-11, Example 19 in pp 14, pp 22-25, Exercises 42-45 in pp 29.
Application emphasis: pp 12-13, exercises 47-54 in pp 20.
Predicates and Quantifiers
Lecture Outline (III)
Tue, Aug 26
Reading:
Rosen, Pages 30-62.
Theory emphasis: pp 31-32, pp 34-36, pp 40, Table 2 pp 41, pp 51-52, Table 1 pp 53.
Application Emphasis: Example 25 pp 43-44, Logic Programming pp 45-46.
Introducion to Proofs
Rules of Logical Inference
Lecture Outline (IV and V)
Thu, Aug 28
Reading:
Rosen, Pages 63-84.
Emphasis: Introduction pp 63, Table 1 pp 66, pp 70-71, pp 75-84,
Introducion to Proofs
Direct proofs
Indirect Proofs: Contradiction, Contraposition
Lecture Outline (IV and V)
Tue, Sept 2
Reading:
Rosen, Pages 63-84.
Emphasis: Introduction pp 63, Table 1 pp 66, pp 70-71, pp 75-84,
Go over Homework 1
Proof Strategies
Lecture Outline (VI and VII)
Thu, Sept 4
Reading:
Rosen, Pages 86-102.
Emphasis: Examples 1, 2, 3, 6, 7, 8, 9, 14, 15, 16, 17 of Section 1.7, Tilings on Pages 97-100.
Proof Strategies (continued)
Direct Proofs, Contradiction, Contraposition, Existential Proofs
Theorems, Lemmas, Claims, Facts, Corollaries
Conjectures and Godel's Incompleteness Theorem (informal discussion)
Lecture Outline (VI and VII)
Tue, Sept 9
Reading:
Rosen, Pages 86-102.
Emphasis: Examples 1, 2, 3, 6, 7, 8, 9, 14, 15, 16, 17 of Section 1.7, Tilings on Pages 97-100.
Two fundamental sums (in computer science and in general):
1+2 +3 + ... + n
1 + x + x^2 + x^3 + ... + x^n
Direct proofs for the above sums
and further demostration of Proof Strategies
Lecture Outline: 1 2
Thu, Sept 11
Reading:
Rosen, Pages 149-158.
Emphasis: pp 150-151, pp 153: Summation Notation, pp 156 Example 13: Double Summation, pp 157 Table 2: Lines 1 and 2
Solutions of Homework 1 pdf
Special Emphasis: Problems 5,6, 7,8 and 10.
These are the type of problems you need to understand for Homework 2 and for next week's Quiz.
Detailed Review of Homework 2 (due Thursday)
Tue, Sept 16
Reading: pdf
Emphasis: Problems 5,6, 7,8 and 10.
How to study for Quiz 1:

From Rosen Book:
Logic: Tables 1,3,4 pp 22-23
Intro Proofs (direct, contrapositive, contradiction): pp 75-78 everything, pp 80-81 everything after Proofs by Contradiction pp 89, example 6

From Outline Lecture Notes:
Lecture Outline (II), pp 1-11
Lecture Outline (III), everything
Lecture Outline (IV) and (V), everything
Lecture Outline (VI) and (VII), everything

Homework 1 Probelms 5,6,7,8,10.
Homework 2 Problems 1,3,4,5,6.
Practice Quiz 1 , everything.
Thu, Sept 18
Reading: See Left
Quiz 1
Tue, Sept 23

Quiz 1
Recursion: a fundamental conceptual primitive
Recursive Definitions and Recursive Algorithms I
The previously studied sums 1+2+...+n and 1+x+...+x^n viewed recursively:
S(n)=S(n-1)+n with S(1)=1 and X(n)=X(n-1)+x^n with X(0)=1
Binary Search T(n)=T(n/2)+1, with T(1)=1, heuristic intuitive solution T(n)=log_2(n)+1
Towers of Hanoi T(n)=2T(n-1)+1, with T(1)=1, heuristic intuitive solution T(n)=2^n+1
Thu, Sept 25
Reading:
Rosen, Pages 294-296.
Recursive Definitions and Recursive Algorithms II
Tiling, Fast Exponantiation
Tue, Sept 30
Reading:
Rosen, Page 277 example 13.
pp 311-314, Algorithms 1,2,3,5 and 6.
The Principle of Induction as a Proof Technique
Strategy: USE THE INDUCTIVE HYPOTHESIS
TO CARRY THE PROOF OF THE INDUCTIVE STEP
Here's outline: 1 2 3 4 5 1 2 3 4
Thu, Oct 2
Reading:
Rosen, Pages 263-269, full proofs.
Rosen, Page 277 example 13, full proof.

Induction as a Proof Technique (II)
Strategy: USE THE INDUCTIVE HYPOTHESIS
TO CARRY THE PROOF OF THE INDUCTIVE STEP
Inductive proofs concerning numbers and sums
(eg 5 divides n^5-n, SUM_1^n(k^2^k)=(n+1)2^{n+1}+2)
Inductive proofs concerning reccurences
eg T(n)=T(n/2)+n, T(1)=1, solves to T(n)=2n(1-1/n)
Tue, Oct 7
Reading:
Rosen, Pages 273, examples 8,9.
Rosen, Page 280, problems 33,34,14.

Induction as a Proof Technique (III)
Strategy: USE THE INDUCTIVE HYPOTHESIS
TO CARRY THE PROOF OF THE INDUCTIVE STEP
Inductive proofs on Structures and Algorithms
(meaning "things" other than numbers)

Inductive proofs concerning reccurences revisited
Mergesort: T(n)=2T(n/2)+n, T(1)=0, solves to T(n)=n log_n(n)
Thu, Oct 9
Reading:
Rosen, Pages 299-303 (Recursively Defined Structures)
Rosen, Pages 303-307 (Structural Induction)
Rosen, Pages 317-321 (Mergesort and its Analysis)

Strong Induction (IV)
Thu, Oct 16
Reading:
Rosen, Pages 283-288.
Growth of Functions
(also extensive review of HW4)
Tue, Oct 21
Reading:
Rosen, Pages 180-188.
Review for Quiz 2 This file

Thu, Oct 23

This file
Quiz 2
Tue, Oct 28

Quiz 2
No Class
Thu, Oct 30

Reading: Solutions to HW 4 and Quiz 2
Growth of Functions
Lecture Outline (I) and Lecture Outline (II)

Tue, Nov 4

Reading: Rosen, pp 180-184, page 187, and Lecture Outline (I) and Lecture Outline (II)
Average and implications, Markov's Inequality
Variance and implications, Chebychev's Inequality
Lecture Outline

Thu, Nov 6

Reading: Lecture Outline
How to make intelligent concusions about large datasets, given small amount of information
Markov and Chebychev's Inequalities revisited

Tue, Nov 11

Reading: Lecture Outline
When Contrapositive and Contradition
are essentially the same proof
and how to not complicate your proofs unecessarily
Thu, Nov 13

Reading: ----
Probability Primitives: (exemplifying probability spaces)
The Monty Hall Problem
Expected Win of Simple Games
Probability in Computer Science:
Overview of Quicksort
Discussion of Randomization in Computationally Hard Problems

Tue, Nov 18

Reading: Rosen pages 393, 394, 398, 400-402, 408-410.
On the relevance of theory and quantitative analysis
Examples:
(1) An argument on the power of recursion from Science Magazine
(2) Some fun puzzles from Martin Gardener's book
Make-up Quiz 2
Thu, Nov 20

Reading: ----
Uniform Distribution
Binomial Distribution, Power-Law Distributions
and their applications
Tue, Nov 25

Reading: ----
Happy Thanksgiving !
Study Guide for Quiz 3 in the Announcement Section (dated Nov 24)
Thu, Nov 27

Quiz 3
Tue, Dec 2

Reading: Quiz 3
The final exam is Friday Dec 12, 11:30-2:20, in the same classroom.
In the final, you are allowed 3 single-sided pages with notes. Any notes you want is fine.
Study Guide for Final (in the order that follows):
Quiz 3, Quiz 2, Practice Quiz 2, HW 6,5,4.
Quiz 1, Practice Quiz 1, Hw 3,2,1.
Thu, Dec 4

Study Guide for Final (in the order that follows):
Quiz 3, Quiz 2, Practice Quiz 2, HW 6,5,4.
Quiz 1, Practice Quiz 1, Hw 3,2,1.