# Automata and Languages Computability Theory Complexity Theory

Save this PDF as:

Size: px
Start display at page:

## Transcription

1 Theory of Computation Chapter 0: Introduction 1

2 What is this course about? This course is about the fundamental capabilities and limitations of computers/computation This course covers 3 areas, which make up the theory of computation: Automata and Languages Computability Theory Complexity Theory 2

3 Automata and Languages Introduces models of computation We will study finite automata and context free grammars Each model determines what can be expressed, as we will see in Part I of this course Will allow us to become familiar with simple models before we move on to more complex models like a Turing machine Given a model, we can examine computability and complexity 3

4 Computability Theory A major mathematical discovery in 1930s Certain problems cannot be solved by computers That is, they have no algorithmic solution We can ask what a model can and can t do As it turns out, a simple model of a computer, A Turing machine, can do everything that a computer can do So we can use a Turing machine to determine what a computer can and can t do (i.e., compute) 4

5 Complexity Theory How hard is a problem? You already should know a lot about this You should know how to determine the time complexity of most simple algorithms You should know the Big O notation. We can say that a problem is O(n 2 ) and that is harder than an O(n) problem We take one step forward and study NP-completeness A first course in theory of computation generally stops there and hence we will not cover Chapters 8, 9, or 10 of the text 5

6 About this Course Theory of Computation traditionally considered challenging I expect (and hope) that you will find this to be true! A very different kind of course In many ways, a pure theory course But very grounded (the models of computation are not abstract at all) Proofs are an integral part of the course, although I and the text both rely on informal proofs But the reasoning must still be clear The only way to learn this material is by doing problems You should expect to spend 3-7 hours per week on homework You should expect to read parts of the text 2-4 times You should not give up if you are completely stumped by a problem after 5 minutes 6

7 Mathematical Preliminaries A review with some new material 7

8 Mathematical Preliminaries We will now very quickly review discrete math You should know most of this from 1100/1400 Reading Chapter 0 of the text should help you review Ask me for help if you have trouble with some of this Mathematical Notation Sets Sequences and Tuples Functions and Relations Graphs Strings and Languages (not covered previously) Boolean Logic Proofs and Types of Proofs You may not have covered natural induction 8

9 Sets A set is a group of objects, order doesn t matter The objects are called elements or members Examples: {1, 3, 5}, {1, 3, 5, }, or {x x Z and x mod 2 0} You should know these operators/concepts Subset (A B or A B) Cardinality: Number elements in set ( A or n(a)) Intersection ( ) and Union ( ), Complement What do we need to know to determine complement of set A? Venn Diagrams: can be used to visualize sets 9

10 Sets II Power Set: All possible subsets of a set If A = {0, 1} then what is P(A)? In general, what is the cardinality of P(B)? 10

11 Sequences and Tuples A sequence is a list of objects, order matters Example: (1, 3, 5) or (5, 3, 1) In this course we will use term tuple instead (1, 3, 5) is a 3-tuple and a k-tuple has k elements 11

12 Sequences and Tuples II Cartesian product (x) is an operation on sets but yields a set of tuples Example: if A = {1, 2} and B = {x, y, z} A x B = {(1,x), (1,y), (1,z), (2,x), (2,y), (2,z)} If we have k sets A 1, A 2,, A k, we can take the Cartesian product A 1 x A 2 x A k which is the set of all k-tuples (a 1, a 2,, a k ) where a i A i We can take Cartesian product of a set with itself A k represents A x A x A x A where there are k A s. The set Z 2 represents Z x Z all pairs of integers, which can be written as {(a,b) a Z and b Z} 12

13 Functions and Relations A function maps an input to a (single) output f(a) = b, f maps a to b The set of possible inputs is the domain and the set of possible outputs is the range f: D R Example 1: for the abs function, if D = Z, what is R? Example 2: sum function Can say Z x Z Z Functions can be described using tables Example: Describe f(x) = 2x for D={1,2,3,4} 13

14 Relations A predicate is a function with range {True, False} Example: even(4) = True A (k-ary) relation is a predicate whose domain is a set of k-tuples A x A x A x A If k =2 then binary relation (e.g., =, <,...) Can just list what is true (even(4)) The text represents the beats relation in Example 0.10 (page 9) using a table and a set Relations have 3 key properties: reflexive, symmetric, transitive A binary relation is an equivalence relation if it has all 3 Try =, <, friend 14

15 Graphs A graph is a set of vertices V and edges E G= (V,E) and can use this to describe a graph A B D C V = {A, B, C, D} E = {(A,B), (A,C), (C,D), (A,D), (B,C)} 15

16 Graphs II Definitions: The degree of a vertex is the number of edges touching it A path is a sequence of nodes connected by edges A simple path does not repeat nodes A path is a cycle if it starts and ends at same node A simple cycle repeats only first and last node A graph is a tree if it is connected and has no simple cycles 16

17 Strings and Languages This is heavily used in this course An alphabet is any non-empty finite set Members of the alphabet are alphabet symbols 1 = {0,1} 2 = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z} 3 = {0,1,a,b,c} A string over an alphabet is a finite sequence of symbols from the alphabet 0100 is a string from 1 and cat is a string from 2 17

18 Strings and Languages II The length of a string w, w is its number of symbols The empty string, ε, has length 0 If w has length n then it can be written as w 1 w 2 w n, where w i Strings can be concatenated ab is string a concatenated with string b a string x can be concatenated with itself k times This is written as x k A language is a set of strings 18

19 Boolean Logic Boolean logic is a mathematical system built around True and False or 0 and 1 Below are the boolean operators, which can be defined by a truth table (and/conjunction) 1 1 = 1; else 0 (or/disjunctions) 0 0 = 1; else 1 (not) 1 = 0 and 0 = 1 (implication) 1 0 = 0; else 1 (equality) 1 1 = 1; 0 0 =1 Can prove equality using truth tables DeMorgan s law and Distributive law 19

20 Proofs Proofs are a big part of this class A proof is a convincing logical argument Proofs in this class need to be clear, but not very formal The books proofs are often informal, using English, so it isn t just that we are being lazy Types of Proofs A B means A if and only if B Prove A B and prove B A Proof by counterexample (prove false via an example) Proof by construction (main proof technique we will use) Proof by contradiction Proof by induction 20

21 Proofs: Example 1 Prove that for every graph G the sum of the degrees of all nodes is even (Ex 0.19, p18 then Theorem 0.21, p20) The book does not really say it, but this is a proof by induction Their informal reasoning: every edge you add touches two vertices and increases the degree of both of these by 1 (i.e., you keep adding 2) A proof by induction means showing it is true for some base case and then that in general if it is true for n, then it is true for n+1 Base case: 0 edges in G means sum-degrees=0, is even Induction step: if sum-degrees even with n edges then show even with n+1 edges When you add an edge, it is by definition between two vertices (but can be the same). Each vertex then has its degree increase by 1, or 2 overall even number + 2 = even (we will accept that for now) 21

22 Proofs: Example 2 For any two sets A and B, (A B) = A B (Theorem 0.20, p 20) Where X means the complement of X We prove sets are equal by showing that they have the same elements What proof technique to use? Any ideas? Prove in each direction: First prove forward direction then backward directions Show if element x is in one of the sets then it is in the other We will do in words, but not as informal as it sounds since we are really using formal definitions of each operator 22

23 Proof: Example 2 (A B) = A B Forward direction (LHS RHS): Assume x (A B) Then x is not in (A B) [defn. of complement] Then x is not in A and x is not in B [defn. of union] So x is in A and x is in B and hence is in RHS Backward direction (RHS LHS) Assume x A B So x A and x B So x A and x B So x not in union (A B) So x must be its complement So we are done! [defn. of intersection] [defn. of complement] [defn. of union] [defn. of complement] 23

24 Proofs: Example 3 For every even number n > 2, there is a 3-regular graph with n nodes (Theorem 0.22, p 21) A graph is k-regular if every node has degree k We will use a proof by construction Many theorems say that a specific type of object exists. One way to prove it exists is by constructing it. May sound weird, but this is probably the most common proof technique we will use in this course We may be asked to show that some property is true. We may need to construct a model which makes it clear that this property is true 24

25 Proof: Example 3 continued Can you construct such a graph for n=4, 6, 8? Try now. If you see a pattern, then generalize it and that is the proof. Hint: place the nodes into a circle Solution: Place the nodes in a circle and then connect each node to the ones next to it, which gives us a 2-regular graph. Then connect each node to the one opposite it and you are done. This is guaranteed to work because if the number of nodes is even, the opposite node will always get hit exactly once. The text describes it more formally. Note that if it was odd, this would not work. 25

26 Proof: Example 4 Jack sees Jill, who has come in from outside. Since Jill is not wet he concludes it is not raining (Ex 0.23, p 22) This is a proof by contradiction. To prove a theorem true by contradiction, assume it is false and show that leads to a contradiction In this case, that translates to assume it is raining and look for contradiction If we know that if it were raining then Jill would be wet, we have a contradiction because Jill is not wet. That is the process, although not a very good example (what if she left the umbrella at the door!) Make sure you go over Theorem 0.24 to prove that square root of 2 is irrational 26

27 More on Proof by Induction Worth going over one more example since some of you may not have used this technique before Please ignore Theorem 0.25, p 24 in text which is how the book explains proof by induction complicated induction proof which is not very illustrative You have a proof by induction for HW1, so the next example should help 27

28 Another Proof by Induction Example Prove that n 2 2n for all n 2, 3, Base case (n=2): 2 2 2x2? Yes. Assume true for n=m and then show it must also be true for n=m+1 So we start with m 2 2m and assume it is true we must show that this requires (m+1) 2 2(m+1) Rewriting we get: m 2 +2m+1 2m+2 Simplifying a bit we get: m 2 1. So, we need to show that m 2 1 given that m 2 2m If 2m 1, then we are done. Is it? Yes, since m itself 2 28

### Mathematics for Computer Science/Software Engineering. Notes for the course MSM1F3 Dr. R. A. Wilson

Mathematics for Computer Science/Software Engineering Notes for the course MSM1F3 Dr. R. A. Wilson October 1996 Chapter 1 Logic Lecture no. 1. We introduce the concept of a proposition, which is a statement

### Automata and Formal Languages

Automata and Formal Languages Winter 2009-2010 Yacov Hel-Or 1 What this course is all about This course is about mathematical models of computation We ll study different machine models (finite automata,

### 2.1 Sets, power sets. Cartesian Products.

Lecture 8 2.1 Sets, power sets. Cartesian Products. Set is an unordered collection of objects. - used to group objects together, - often the objects with similar properties This description of a set (without

### Clicker Question. Theorems/Proofs and Computational Problems/Algorithms MC215: MATHEMATICAL REASONING AND DISCRETE STRUCTURES

MC215: MATHEMATICAL REASONING AND DISCRETE STRUCTURES Tuesday, 1/21/14 General course Information Sets Reading: [J] 1.1 Optional: [H] 1.1-1.7 Exercises: Do before next class; not to hand in [J] pp. 12-14:

### Sets and set operations

CS 441 Discrete Mathematics for CS Lecture 7 Sets and set operations Milos Hauskrecht milos@cs.pitt.edu 5329 Sennott Square asic discrete structures Discrete math = study of the discrete structures used

### Reading 13 : Finite State Automata and Regular Expressions

CS/Math 24: Introduction to Discrete Mathematics Fall 25 Reading 3 : Finite State Automata and Regular Expressions Instructors: Beck Hasti, Gautam Prakriya In this reading we study a mathematical model

### Formal Languages and Automata Theory - Regular Expressions and Finite Automata -

Formal Languages and Automata Theory - Regular Expressions and Finite Automata - Samarjit Chakraborty Computer Engineering and Networks Laboratory Swiss Federal Institute of Technology (ETH) Zürich March

### Announcements. CompSci 230 Discrete Math for Computer Science Sets. Introduction to Sets. Sets

CompSci 230 Discrete Math for Computer Science Sets September 12, 2013 Prof. Rodger Slides modified from Rosen 1 nnouncements Read for next time Chap. 2.3-2.6 Homework 2 due Tuesday Recitation 3 on Friday

### Homework 5 Solutions

Homework 5 Solutions 4.2: 2: a. 321 = 256 + 64 + 1 = (01000001) 2 b. 1023 = 512 + 256 + 128 + 64 + 32 + 16 + 8 + 4 + 2 + 1 = (1111111111) 2. Note that this is 1 less than the next power of 2, 1024, which

### Lecture 16 : Relations and Functions DRAFT

CS/Math 240: Introduction to Discrete Mathematics 3/29/2011 Lecture 16 : Relations and Functions Instructor: Dieter van Melkebeek Scribe: Dalibor Zelený DRAFT In Lecture 3, we described a correspondence

### 6.045: Automata, Computability, and Complexity Or, Great Ideas in Theoretical Computer Science Spring, 2010. Class 4 Nancy Lynch

6.045: Automata, Computability, and Complexity Or, Great Ideas in Theoretical Computer Science Spring, 2010 Class 4 Nancy Lynch Today Two more models of computation: Nondeterministic Finite Automata (NFAs)

### Sections 2.1, 2.2 and 2.4

SETS Sections 2.1, 2.2 and 2.4 Chapter Summary Sets The Language of Sets Set Operations Set Identities Introduction Sets are one of the basic building blocks for the types of objects considered in discrete

### Applications of Methods of Proof

CHAPTER 4 Applications of Methods of Proof 1. Set Operations 1.1. Set Operations. The set-theoretic operations, intersection, union, and complementation, defined in Chapter 1.1 Introduction to Sets are

### Chapter 3. Cartesian Products and Relations. 3.1 Cartesian Products

Chapter 3 Cartesian Products and Relations The material in this chapter is the first real encounter with abstraction. Relations are very general thing they are a special type of subset. After introducing

### WOLLONGONG COLLEGE AUSTRALIA. Diploma in Information Technology

First Name: Family Name: Student Number: Class/Tutorial: WOLLONGONG COLLEGE AUSTRALIA A College of the University of Wollongong Diploma in Information Technology Final Examination Spring Session 2008 WUCT121

### Elementary Number Theory and Methods of Proof. CSE 215, Foundations of Computer Science Stony Brook University http://www.cs.stonybrook.

Elementary Number Theory and Methods of Proof CSE 215, Foundations of Computer Science Stony Brook University http://www.cs.stonybrook.edu/~cse215 1 Number theory Properties: 2 Properties of integers (whole

### CmSc 175 Discrete Mathematics Lesson 10: SETS A B, A B

CmSc 175 Discrete Mathematics Lesson 10: SETS Sets: finite, infinite, : empty set, U : universal set Describing a set: Enumeration = {a, b, c} Predicates = {x P(x)} Recursive definition, e.g. sequences

### Cartesian Products and Relations

Cartesian Products and Relations Definition (Cartesian product) If A and B are sets, the Cartesian product of A and B is the set A B = {(a, b) :(a A) and (b B)}. The following points are worth special

### Automata Theory. Şubat 2006 Tuğrul Yılmaz Ankara Üniversitesi

Automata Theory Automata theory is the study of abstract computing devices. A. M. Turing studied an abstract machine that had all the capabilities of today s computers. Turing s goal was to describe the

### 2.1 The Algebra of Sets

Chapter 2 Abstract Algebra 83 part of abstract algebra, sets are fundamental to all areas of mathematics and we need to establish a precise language for sets. We also explore operations on sets and relations

### Regular Languages and Finite State Machines

Regular Languages and Finite State Machines Plan for the Day: Mathematical preliminaries - some review One application formal definition of finite automata Examples 1 Sets A set is an unordered collection

### Lecture 17 : Equivalence and Order Relations DRAFT

CS/Math 240: Introduction to Discrete Mathematics 3/31/2011 Lecture 17 : Equivalence and Order Relations Instructor: Dieter van Melkebeek Scribe: Dalibor Zelený DRAFT Last lecture we introduced the notion

### Lecture 1. Basic Concepts of Set Theory, Functions and Relations

September 7, 2005 p. 1 Lecture 1. Basic Concepts of Set Theory, Functions and Relations 0. Preliminaries...1 1. Basic Concepts of Set Theory...1 1.1. Sets and elements...1 1.2. Specification of sets...2

### 1.1 Logical Form and Logical Equivalence 1

Contents Chapter I The Logic of Compound Statements 1.1 Logical Form and Logical Equivalence 1 Identifying logical form; Statements; Logical connectives: not, and, and or; Translation to and from symbolic

### Examination paper for MA0301 Elementær diskret matematikk

Department of Mathematical Sciences Examination paper for MA0301 Elementær diskret matematikk Academic contact during examination: Iris Marjan Smit a, Sverre Olaf Smalø b Phone: a 9285 0781, b 7359 1750

### 6.080 / 6.089 Great Ideas in Theoretical Computer Science Spring 2008

MIT OpenCourseWare http://ocw.mit.edu 6.080 / 6.089 Great Ideas in Theoretical Computer Science Spring 2008 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms.

### Induction. Margaret M. Fleck. 10 October These notes cover mathematical induction and recursive definition

Induction Margaret M. Fleck 10 October 011 These notes cover mathematical induction and recursive definition 1 Introduction to induction At the start of the term, we saw the following formula for computing

### Midterm Practice Problems

6.042/8.062J Mathematics for Computer Science October 2, 200 Tom Leighton, Marten van Dijk, and Brooke Cowan Midterm Practice Problems Problem. [0 points] In problem set you showed that the nand operator

### Properties of Real Numbers

16 Chapter P Prerequisites P.2 Properties of Real Numbers What you should learn: Identify and use the basic properties of real numbers Develop and use additional properties of real numbers Why you should

### 3. Mathematical Induction

3. MATHEMATICAL INDUCTION 83 3. Mathematical Induction 3.1. First Principle of Mathematical Induction. Let P (n) be a predicate with domain of discourse (over) the natural numbers N = {0, 1,,...}. If (1)

### 6.3 Conditional Probability and Independence

222 CHAPTER 6. PROBABILITY 6.3 Conditional Probability and Independence Conditional Probability Two cubical dice each have a triangle painted on one side, a circle painted on two sides and a square painted

### MATH10040 Chapter 2: Prime and relatively prime numbers

MATH10040 Chapter 2: Prime and relatively prime numbers Recall the basic definition: 1. Prime numbers Definition 1.1. Recall that a positive integer is said to be prime if it has precisely two positive

### CS 3719 (Theory of Computation and Algorithms) Lecture 4

CS 3719 (Theory of Computation and Algorithms) Lecture 4 Antonina Kolokolova January 18, 2012 1 Undecidable languages 1.1 Church-Turing thesis Let s recap how it all started. In 1990, Hilbert stated a

### INTRODUCTORY SET THEORY

M.Sc. program in mathematics INTRODUCTORY SET THEORY Katalin Károlyi Department of Applied Analysis, Eötvös Loránd University H-1088 Budapest, Múzeum krt. 6-8. CONTENTS 1. SETS Set, equal sets, subset,

### Computability Theory

CSC 438F/2404F Notes (S. Cook and T. Pitassi) Fall, 2014 Computability Theory This section is partly inspired by the material in A Course in Mathematical Logic by Bell and Machover, Chap 6, sections 1-10.

### Outline. NP-completeness. When is a problem easy? When is a problem hard? Today. Euler Circuits

Outline NP-completeness Examples of Easy vs. Hard problems Euler circuit vs. Hamiltonian circuit Shortest Path vs. Longest Path 2-pairs sum vs. general Subset Sum Reducing one problem to another Clique

### INCIDENCE-BETWEENNESS GEOMETRY

INCIDENCE-BETWEENNESS GEOMETRY MATH 410, CSUSM. SPRING 2008. PROFESSOR AITKEN This document covers the geometry that can be developed with just the axioms related to incidence and betweenness. The full

### Incenter Circumcenter

TRIANGLE: Centers: Incenter Incenter is the center of the inscribed circle (incircle) of the triangle, it is the point of intersection of the angle bisectors of the triangle. The radius of incircle is

### Mathematical induction. Niloufar Shafiei

Mathematical induction Niloufar Shafiei Mathematical induction Mathematical induction is an extremely important proof technique. Mathematical induction can be used to prove results about complexity of

### 4.1. Definitions. A set may be viewed as any well defined collection of objects, called elements or members of the set.

Section 4. Set Theory 4.1. Definitions A set may be viewed as any well defined collection of objects, called elements or members of the set. Sets are usually denoted with upper case letters, A, B, X, Y,

### We give a basic overview of the mathematical background required for this course.

1 Background We give a basic overview of the mathematical background required for this course. 1.1 Set Theory We introduce some concepts from naive set theory (as opposed to axiomatic set theory). The

### Answer Key for California State Standards: Algebra I

Algebra I: Symbolic reasoning and calculations with symbols are central in algebra. Through the study of algebra, a student develops an understanding of the symbolic language of mathematics and the sciences.

### Full and Complete Binary Trees

Full and Complete Binary Trees Binary Tree Theorems 1 Here are two important types of binary trees. Note that the definitions, while similar, are logically independent. Definition: a binary tree T is full

### 3. Equivalence Relations. Discussion

3. EQUIVALENCE RELATIONS 33 3. Equivalence Relations 3.1. Definition of an Equivalence Relations. Definition 3.1.1. A relation R on a set A is an equivalence relation if and only if R is reflexive, symmetric,

### Discrete Mathematics

Discrete Mathematics Chih-Wei Yi Dept. of Computer Science National Chiao Tung University March 16, 2009 2.1 Sets 2.1 Sets 2.1 Sets Basic Notations for Sets For sets, we ll use variables S, T, U,. We can

### Discrete Mathematics Problems

Discrete Mathematics Problems William F. Klostermeyer School of Computing University of North Florida Jacksonville, FL 32224 E-mail: wkloster@unf.edu Contents 0 Preface 3 1 Logic 5 1.1 Basics...............................

### POWER SETS AND RELATIONS

POWER SETS AND RELATIONS L. MARIZZA A. BAILEY 1. The Power Set Now that we have defined sets as best we can, we can consider a sets of sets. If we were to assume nothing, except the existence of the empty

### Discrete Mathematics Lecture 3 Elementary Number Theory and Methods of Proof. Harper Langston New York University

Discrete Mathematics Lecture 3 Elementary Number Theory and Methods of Proof Harper Langston New York University Proof and Counterexample Discovery and proof Even and odd numbers number n from Z is called

### 13 Infinite Sets. 13.1 Injections, Surjections, and Bijections. mcs-ftl 2010/9/8 0:40 page 379 #385

mcs-ftl 2010/9/8 0:40 page 379 #385 13 Infinite Sets So you might be wondering how much is there to say about an infinite set other than, well, it has an infinite number of elements. Of course, an infinite

### 7 Relations and Functions

7 Relations and Functions In this section, we introduce the concept of relations and functions. Relations A relation R from a set A to a set B is a set of ordered pairs (a, b), where a is a member of A,

### 136 CHAPTER 4. INDUCTION, GRAPHS AND TREES

136 TER 4. INDUCTION, GRHS ND TREES 4.3 Graphs In this chapter we introduce a fundamental structural idea of discrete mathematics, that of a graph. Many situations in the applications of discrete mathematics

### Solutions to In-Class Problems Week 4, Mon.

Massachusetts Institute of Technology 6.042J/18.062J, Fall 05: Mathematics for Computer Science September 26 Prof. Albert R. Meyer and Prof. Ronitt Rubinfeld revised September 26, 2005, 1050 minutes Solutions

### MODULAR ARITHMETIC. a smallest member. It is equivalent to the Principle of Mathematical Induction.

MODULAR ARITHMETIC 1 Working With Integers The usual arithmetic operations of addition, subtraction and multiplication can be performed on integers, and the result is always another integer Division, on

### Elementary Number Theory We begin with a bit of elementary number theory, which is concerned

CONSTRUCTION OF THE FINITE FIELDS Z p S. R. DOTY Elementary Number Theory We begin with a bit of elementary number theory, which is concerned solely with questions about the set of integers Z = {0, ±1,

### Session 6 Number Theory

Key Terms in This Session Session 6 Number Theory Previously Introduced counting numbers factor factor tree prime number New in This Session composite number greatest common factor least common multiple

### The Halting Problem is Undecidable

185 Corollary G = { M, w w L(M) } is not Turing-recognizable. Proof. = ERR, where ERR is the easy to decide language: ERR = { x { 0, 1 }* x does not have a prefix that is a valid code for a Turing machine

### SETS AND FUNCTIONS, MATH 215 FALL 2015 (WHYTE)

SETS AND FUNCTIONS, MATH 215 FALL 2015 (WHYTE) 1. Intro to Sets After some work with numbers, we want to talk about sets. For our purposes, sets are just collections of objects. These objects can be anything

### WRITING PROOFS. Christopher Heil Georgia Institute of Technology

WRITING PROOFS Christopher Heil Georgia Institute of Technology A theorem is just a statement of fact A proof of the theorem is a logical explanation of why the theorem is true Many theorems have this

### Discrete Mathematics: Solutions to Homework (12%) For each of the following sets, determine whether {2} is an element of that set.

Discrete Mathematics: Solutions to Homework 2 1. (12%) For each of the following sets, determine whether {2} is an element of that set. (a) {x R x is an integer greater than 1} (b) {x R x is the square

### Math 3000 Section 003 Intro to Abstract Math Homework 2

Math 3000 Section 003 Intro to Abstract Math Homework 2 Department of Mathematical and Statistical Sciences University of Colorado Denver, Spring 2012 Solutions (February 13, 2012) Please note that these

### Equations and Inequalities

Rational Equations Overview of Objectives, students should be able to: 1. Solve rational equations with variables in the denominators.. Recognize identities, conditional equations, and inconsistent equations.

### L - Standard Letter Grade P - Pass/No Pass Repeatability: N - Course may not be repeated

Course: MATH 26 Division: 10 Also Listed As: 200930, INACTIVE COURSE Short Title: Full Title: DISCRETE MATHEMATIC Discrete Mathematics Contact Hours/Week Lecture: 4 Lab: 0 Other: 0 Total: 4 4 Number of

### Finite Automata. Reading: Chapter 2

Finite Automata Reading: Chapter 2 1 Finite Automaton (FA) Informally, a state diagram that comprehensively captures all possible states and transitions that a machine can take while responding to a stream

### 6.080 / 6.089 Great Ideas in Theoretical Computer Science Spring 2008

MIT OpenCourseWare http://ocw.mit.edu 6.080 / 6.089 Great Ideas in Theoretical Computer Science Spring 2008 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms.

### CS 441 Discrete Mathematics for CS Lecture 5. Predicate logic. CS 441 Discrete mathematics for CS. Negation of quantifiers

CS 441 Discrete Mathematics for CS Lecture 5 Predicate logic Milos Hauskrecht milos@cs.pitt.edu 5329 Sennott Square Negation of quantifiers English statement: Nothing is perfect. Translation: x Perfect(x)

### 8 Divisibility and prime numbers

8 Divisibility and prime numbers 8.1 Divisibility In this short section we extend the concept of a multiple from the natural numbers to the integers. We also summarize several other terms that express

### Week 5: Binary Relations

1 Binary Relations Week 5: Binary Relations The concept of relation is common in daily life and seems intuitively clear. For instance, let X be the set of all living human females and Y the set of all

### Why? A central concept in Computer Science. Algorithms are ubiquitous.

Analysis of Algorithms: A Brief Introduction Why? A central concept in Computer Science. Algorithms are ubiquitous. Using the Internet (sending email, transferring files, use of search engines, online

### Basic Set Theory. 1. Motivation. Fido Sue. Fred Aristotle Bob. LX 502 - Semantics I September 11, 2008

Basic Set Theory LX 502 - Semantics I September 11, 2008 1. Motivation When you start reading these notes, the first thing you should be asking yourselves is What is Set Theory and why is it relevant?

### 2.1. Inductive Reasoning EXAMPLE A

CONDENSED LESSON 2.1 Inductive Reasoning In this lesson you will Learn how inductive reasoning is used in science and mathematics Use inductive reasoning to make conjectures about sequences of numbers

### The Foundations: Logic and Proofs. Chapter 1, Part III: Proofs

The Foundations: Logic and Proofs Chapter 1, Part III: Proofs Rules of Inference Section 1.6 Section Summary Valid Arguments Inference Rules for Propositional Logic Using Rules of Inference to Build Arguments

### Chapter 11 Number Theory

Chapter 11 Number Theory Number theory is one of the oldest branches of mathematics. For many years people who studied number theory delighted in its pure nature because there were few practical applications

### Basic Concepts of Set Theory, Functions and Relations

March 1, 2006 p. 1 Basic Concepts of Set Theory, Functions and Relations 1. Basic Concepts of Set Theory...1 1.1. Sets and elements...1 1.2. Specification of sets...2 1.3. Identity and cardinality...3

### 1 Introduction to Counting

1 Introduction to Counting 1.1 Introduction In this chapter you will learn the fundamentals of enumerative combinatorics, the branch of mathematics concerned with counting. While enumeration problems can

### CAs and Turing Machines. The Basis for Universal Computation

CAs and Turing Machines The Basis for Universal Computation What We Mean By Universal When we claim universal computation we mean that the CA is capable of calculating anything that could possibly be calculated*.

### Mathematics for Computer Science

Mathematics for Computer Science Lecture 2: Functions and equinumerous sets Areces, Blackburn and Figueira TALARIS team INRIA Nancy Grand Est Contact: patrick.blackburn@loria.fr Course website: http://www.loria.fr/~blackbur/courses/math

### Mathematical Induction. Lecture 10-11

Mathematical Induction Lecture 10-11 Menu Mathematical Induction Strong Induction Recursive Definitions Structural Induction Climbing an Infinite Ladder Suppose we have an infinite ladder: 1. We can reach

### (IALC, Chapters 8 and 9) Introduction to Turing s life, Turing machines, universal machines, unsolvable problems.

3130CIT: Theory of Computation Turing machines and undecidability (IALC, Chapters 8 and 9) Introduction to Turing s life, Turing machines, universal machines, unsolvable problems. An undecidable problem

### Discrete Maths. Philippa Gardner. These lecture notes are based on previous notes by Iain Phillips.

Discrete Maths Philippa Gardner These lecture notes are based on previous notes by Iain Phillips. This short course introduces some basic concepts in discrete mathematics: sets, relations, and functions.

### 24 Uses of Turing Machines

Formal Language and Automata Theory: CS2004 24 Uses of Turing Machines 24 Introduction We have previously covered the application of Turing Machine as a recognizer and decider In this lecture we will discuss

### Florida State University Course Notes MAD 2104 Discrete Mathematics I

Florida State University Course Notes MAD 2104 Discrete Mathematics I Florida State University Tallahassee, Florida 32306-4510 Copyright c 2011 Florida State University Written by Dr. John Bryant and Dr.

### Chapter 7: Products and quotients

Chapter 7: Products and quotients Matthew Macauley Department of Mathematical Sciences Clemson University http://www.math.clemson.edu/~macaule/ Math 42, Spring 24 M. Macauley (Clemson) Chapter 7: Products

### A Little Set Theory (Never Hurt Anybody)

A Little Set Theory (Never Hurt Anybody) Matthew Saltzman Department of Mathematical Sciences Clemson University Draft: August 21, 2013 1 Introduction The fundamental ideas of set theory and the algebra

### Introduction to Automata Theory. Reading: Chapter 1

Introduction to Automata Theory Reading: Chapter 1 1 What is Automata Theory? Study of abstract computing devices, or machines Automaton = an abstract computing device Note: A device need not even be a

### CSE140: Midterm 1 Solution and Rubric

CSE140: Midterm 1 Solution and Rubric April 23, 2014 1 Short Answers 1.1 True or (6pts) 1. A maxterm must include all input variables (1pt) True 2. A canonical product of sums is a product of minterms

### CHAPTER 3. Methods of Proofs. 1. Logical Arguments and Formal Proofs

CHAPTER 3 Methods of Proofs 1. Logical Arguments and Formal Proofs 1.1. Basic Terminology. An axiom is a statement that is given to be true. A rule of inference is a logical rule that is used to deduce

### Graph Theory Problems and Solutions

raph Theory Problems and Solutions Tom Davis tomrdavis@earthlink.net http://www.geometer.org/mathcircles November, 005 Problems. Prove that the sum of the degrees of the vertices of any finite graph is

### Geometry Chapter 2: Geometric Reasoning Lesson 1: Using Inductive Reasoning to Make Conjectures Inductive Reasoning:

Geometry Chapter 2: Geometric Reasoning Lesson 1: Using Inductive Reasoning to Make Conjectures Inductive Reasoning: Conjecture: Advantages: can draw conclusions from limited information helps us to organize

### Factoring Patterns in the Gaussian Plane

Factoring Patterns in the Gaussian Plane Steve Phelps Introduction This paper describes discoveries made at the Park City Mathematics Institute, 00, as well as some proofs. Before the summer I understood

### CLASS 3, GIVEN ON 9/27/2010, FOR MATH 25, FALL 2010

CLASS 3, GIVEN ON 9/27/2010, FOR MATH 25, FALL 2010 1. Greatest common divisor Suppose a, b are two integers. If another integer d satisfies d a, d b, we call d a common divisor of a, b. Notice that as

### Automata and Computability. Solutions to Exercises

Automata and Computability Solutions to Exercises Fall 25 Alexis Maciel Department of Computer Science Clarkson University Copyright c 25 Alexis Maciel ii Contents Preface vii Introduction 2 Finite Automata

### CONTENTS 1. Peter Kahn. Spring 2007

CONTENTS 1 MATH 304: CONSTRUCTING THE REAL NUMBERS Peter Kahn Spring 2007 Contents 2 The Integers 1 2.1 The basic construction.......................... 1 2.2 Adding integers..............................

### Pythagorean Triples. Chapter 2. a 2 + b 2 = c 2

Chapter Pythagorean Triples The Pythagorean Theorem, that beloved formula of all high school geometry students, says that the sum of the squares of the sides of a right triangle equals the square of the

### 6.080/6.089 GITCS Feb 12, 2008. Lecture 3

6.8/6.89 GITCS Feb 2, 28 Lecturer: Scott Aaronson Lecture 3 Scribe: Adam Rogal Administrivia. Scribe notes The purpose of scribe notes is to transcribe our lectures. Although I have formal notes of my

### Vieta s Formulas and the Identity Theorem

Vieta s Formulas and the Identity Theorem This worksheet will work through the material from our class on 3/21/2013 with some examples that should help you with the homework The topic of our discussion

### 1. True or False? A voltage level in the range 0 to 2 volts is interpreted as a binary 1.

File: chap04, Chapter 04 1. True or False? A voltage level in the range 0 to 2 volts is interpreted as a binary 1. 2. True or False? A gate is a device that accepts a single input signal and produces one

### Discrete Mathematics and Probability Theory Fall 2009 Satish Rao, David Tse Note 2

CS 70 Discrete Mathematics and Probability Theory Fall 2009 Satish Rao, David Tse Note 2 Proofs Intuitively, the concept of proof should already be familiar We all like to assert things, and few of us

### Discrete Mathematics and Probability Theory Fall 2009 Satish Rao,David Tse Note 11

CS 70 Discrete Mathematics and Probability Theory Fall 2009 Satish Rao,David Tse Note Conditional Probability A pharmaceutical company is marketing a new test for a certain medical condition. According