Discrete Structures of Computer Science Propositional Logic I

Size: px
Start display at page:

Download "Discrete Structures of Computer Science Propositional Logic I"

Transcription

1 Discrete Structures of Computer Science Propositional Logic I Gazihan Alankuş (Based on original slides by Brahim Hnich) July 26, 2012

2 1 Use of Logic 2 Statements 3 Logic Connectives 4 Truth Tables

3 Use of Logic In mathematics:

4 Use of Logic In mathematics: Give precise meaning to statements

5 Use of Logic In mathematics: Give precise meaning to statements Distinguish between valid and invalid arguments

6 Use of Logic In mathematics: Give precise meaning to statements Distinguish between valid and invalid arguments Provide use of correct reasoning

7 Use of Logic In mathematics: Give precise meaning to statements Distinguish between valid and invalid arguments Provide use of correct reasoning Natural language can be very ambiguous

8 Use of Logic In mathematics: Give precise meaning to statements Distinguish between valid and invalid arguments Provide use of correct reasoning Natural language can be very ambiguous He ate the cookies on the couch

9 Use of Logic In mathematics: Give precise meaning to statements Distinguish between valid and invalid arguments Provide use of correct reasoning Natural language can be very ambiguous He ate the cookies on the couch This is good soup

10 Use of Logic In mathematics: Give precise meaning to statements Distinguish between valid and invalid arguments Provide use of correct reasoning Natural language can be very ambiguous He ate the cookies on the couch This is good soup You could do with a new automobile. How about a test drive?

11 Use of Logic In computing:

12 Use of Logic In computing: Design new data/knowledge from existing facts

13 Use of Logic In computing: Design new data/knowledge from existing facts Design of computer circuits

14 Use of Logic In computing: Design new data/knowledge from existing facts Design of computer circuits Construction of computer programs

15 Use of Logic In computing: Design new data/knowledge from existing facts Design of computer circuits Construction of computer programs Verification of correctness of programs and circuit design

16 Use of Logic In computing: Design new data/knowledge from existing facts Design of computer circuits Construction of computer programs Verification of correctness of programs and circuit design Specification

17 Statements(propositions) Propositional logic deals with statements and their truth values

18 Statements(propositions) Propositional logic deals with statements and their truth values A statement is a declarative sentence that can be true or false

19 Statements(propositions) Propositional logic deals with statements and their truth values A statement is a declarative sentence that can be true or false Truth values are TRUE (T or 1) and FALSE (F or 0)

20 Example Statements = 2 (statement, T)

21 Example Statements = 2 (statement, T) The moon is made of cheese (statement, F)

22 Example Statements = 2 (statement, T) The moon is made of cheese (statement, F) Go home! (no statement, imperative)

23 Example Statements = 2 (statement, T) The moon is made of cheese (statement, F) Go home! (no statement, imperative) What a beautiful garden (not statement, exclamation)

24 Example Statements = 2 (statement, T) The moon is made of cheese (statement, F) Go home! (no statement, imperative) What a beautiful garden (not statement, exclamation) Alice said: What a beautiful garden! (statement, depends on Alice)

25 Example Statements = 2 (statement, T) The moon is made of cheese (statement, F) Go home! (no statement, imperative) What a beautiful garden (not statement, exclamation) Alice said: What a beautiful garden! (statement, depends on Alice) y + 1 = 2 (not statement, uncertain)

26 Compound Statements Simplest statements are called primitive statements

27 Compound Statements Simplest statements are called primitive statements We shall use propositional variables to denote primitive statements, p, q, r,...

28 Compound Statements Simplest statements are called primitive statements We shall use propositional variables to denote primitive statements, p, q, r,... We cannot decide the truth value of a primitive statement. This is not what logic does

29 Compound Statements Simplest statements are called primitive statements We shall use propositional variables to denote primitive statements, p, q, r,... We cannot decide the truth value of a primitive statement. This is not what logic does Instead we combine primitive statements by means of logic connectives into compound statements or formulas and look how the truth value of a compound statement depends on the truth values of the primitive statements it includes.

30 Compound Statements Simplest statements are called primitive statements We shall use propositional variables to denote primitive statements, p, q, r,... We cannot decide the truth value of a primitive statement. This is not what logic does Instead we combine primitive statements by means of logic connectives into compound statements or formulas and look how the truth value of a compound statement depends on the truth values of the primitive statements it includes. We will denote compound statements by Θ, Ψ,...

31 Logic connectives negation (not, ) It is not true that at least one politician was honest

32 Logic connectives negation (not, ) It is not true that at least one politician was honest conjunction (and, ) In this room there is a lady, and in the other room there is a tiger

33 Logic connectives negation (not, ) It is not true that at least one politician was honest conjunction (and, ) In this room there is a lady, and in the other room there is a tiger disjunction (or, ) This is a matter of death or life!

34 Logic Connectives implication (if... then..., ) If it rains, then we get wet

35 Logic Connectives implication (if... then..., ) If it rains, then we get wet exclusive or (either... or..., ) Either there is a tiger in this room, or a lady

36 Logic Connectives implication (if... then..., ) If it rains, then we get wet exclusive or (either... or..., ) Either there is a tiger in this room, or a lady equivalence (if and only if, ) There is a lady in this room if and only if there is a tiger in the other room!

37 Truth Tables Truth tables is a way to specify the exact truth value of a compound statement through the values of primitive statements involved

38 Truth Table of Negation Unary connective p p F (0) T (1) T (1) F (0) p: Today is Monday p: Today is not Monday

39 Truth Table of Conjunction Binary connective p q p q p: Today is Monday q: It is raining p q: Today is Monday and it is raining

40 Truth Table of Disjunction Binary connective p q p q p: Today is Friday q: Today is Saturday p q: Today is Friday or Saturday

41 Truth Table of exclusive or Binary connective p q p q p q: You can follow the rules or be disqualified

42 Truth Table of implication Binary connective p q p q p q: If black is white, then we we live in Antartica

43 Implication as a promise Note that logical implication does not assume any causal connection. Implication can be thought of as a promise, and it is true if the promise is kept. If I am elected, then I will lower taxes He is not elected and taxes are not lowered He is not elected and taxes are lowered He is elected and taxes are not lowered He is elected and taxes are lowered promise kept! promise kept! promise broken! promise kept!

44 Playing with implication Parts of implication p q p: can be viewed as a hypothesis, antecedent, premise q: can be viewed as a conclusion or consequence if p then q q follows from p a necessary condition for p is q if p, q p implies q a sufficient condition for q is p p is sufficient for q p only if q q if p q whenever p

45 Playing with implication Converse, contrapositive, and inverse p q: If it is raining then the home team wins Contrapositive q p If the home team does not win, then it is not raining Converse q p If the home team wins, then it is raining Inverse p q If it is not raining, then the home team does not win

46 Truth Table of equivalence Binary connective p q p q p q: You pass this if and only if you work hard p q: You can take the flight if and only if you buy a ticket

47 Tautologies Tautology is a compound statement (formula) that is true for all combinations of truth values of its propositional variables p p p p p p

48 Tautologies Tautology is a compound statement (formula) that is true for all combinations of truth values of its propositional variables (p q) (q p) p q p q q p (p q) (q p)

49 Contradictions Contradiction is a compound statement (formula) that is false for all combinations of truth values of its propositional variables p p p p p p

50 Contradictions Contradiction is a compound statement (formula) that is false for all combinations of truth values of its propositional variables (p q) (p q) p q (p q) (p q)

51 Example Construct the truth table of the following compound statement p (p q)

52 Example Construct the truth table of the following compound statement p (p q) p q q p q p (p q)

Introduction Propositional Logic. Discrete Mathematics Andrei Bulatov

Introduction Propositional Logic. Discrete Mathematics Andrei Bulatov Introduction Propositional Logic Discrete Mathematics Andrei Bulatov Discrete Mathematics Propositional Logic 2-2 What is Logic? Computer science is a mere continuation of logic by other means Georg Gottlob

More information

CSC Discrete Math I, Spring Propositional Logic

CSC Discrete Math I, Spring Propositional Logic CSC 125 - Discrete Math I, Spring 2017 Propositional Logic Propositions A proposition is a declarative sentence that is either true or false Propositional Variables A propositional variable (p, q, r, s,...)

More information

Discrete Structures of Computer Science Propositional Logic III Rules of Inference

Discrete Structures of Computer Science Propositional Logic III Rules of Inference Discrete Structures of Computer Science Propositional Logic III Rules of Inference Gazihan Alankuş (Based on original slides by Brahim Hnich) July 30, 2012 1 Previous Lecture 2 Summary of Laws of Logic

More information

Compound Propositions

Compound Propositions Discrete Structures Compound Propositions Producing new propositions from existing propositions. Logical Operators or Connectives 1. Not 2. And 3. Or 4. Exclusive or 5. Implication 6. Biconditional Truth

More information

CHAPTER 1 - LOGIC OF COMPOUND STATEMENTS

CHAPTER 1 - LOGIC OF COMPOUND STATEMENTS CHAPTER 1 - LOGIC OF COMPOUND STATEMENTS 1.1 - Logical Form and Logical Equivalence Definition. A statement or proposition is a sentence that is either true or false, but not both. ex. 1 + 2 = 3 IS a statement

More information

Lecture 2. Logic Compound Statements Conditional Statements Valid & Invalid Arguments Digital Logic Circuits. Reading (Epp s textbook)

Lecture 2. Logic Compound Statements Conditional Statements Valid & Invalid Arguments Digital Logic Circuits. Reading (Epp s textbook) Lecture 2 Logic Compound Statements Conditional Statements Valid & Invalid Arguments Digital Logic Circuits Reading (Epp s textbook) 2.1-2.4 1 Logic Logic is a system based on statements. A statement (or

More information

What is Logic? Introduction to Logic. Simple Statements. Which one is statement?

What is Logic? Introduction to Logic. Simple Statements. Which one is statement? What is Logic? Introduction to Logic Peter Lo Logic is the study of reasoning It is specifically concerned with whether reasoning is correct Logic is also known as Propositional Calculus CS218 Peter Lo

More information

PROPOSITIONAL CALCULUS

PROPOSITIONAL CALCULUS PROPOSITIONAL CALCULUS A proposition is a complete declarative sentence that is either TRUE (truth value T or 1) or FALSE (truth value F or 0), but not both. These are not propositions! Connectives and

More information

Chapter 1, Part I: Propositional Logic. With Question/Answer Animations

Chapter 1, Part I: Propositional Logic. With Question/Answer Animations Chapter 1, Part I: Propositional Logic With Question/Answer Animations Chapter Summary Propositional Logic The Language of Propositions Applications Logical Equivalences Predicate Logic The Language of

More information

software design & management Gachon University Chulyun Kim

software design & management Gachon University Chulyun Kim Gachon University Chulyun Kim 2 Outline Propositional Logic Propositional Equivalences Predicates and Quantifiers Nested Quantifiers Rules of Inference Introduction to Proofs 3 1.1 Propositional Logic

More information

Chapter Summary. Propositional Logic. Predicate Logic. Proofs. The Language of Propositions (1.1) Applications (1.2) Logical Equivalences (1.

Chapter Summary. Propositional Logic. Predicate Logic. Proofs. The Language of Propositions (1.1) Applications (1.2) Logical Equivalences (1. Chapter 1 Chapter Summary Propositional Logic The Language of Propositions (1.1) Applications (1.2) Logical Equivalences (1.3) Predicate Logic The Language of Quantifiers (1.4) Logical Equivalences (1.4)

More information

2. The Logic of Compound Statements Summary. Aaron Tan August 2017

2. The Logic of Compound Statements Summary. Aaron Tan August 2017 2. The Logic of Compound Statements Summary Aaron Tan 21 25 August 2017 1 2. The Logic of Compound Statements 2.1 Logical Form and Logical Equivalence Statements; Compound Statements; Statement Form (Propositional

More information

2.2: Logical Equivalence: The Laws of Logic

2.2: Logical Equivalence: The Laws of Logic Example (2.7) For primitive statement p and q, construct a truth table for each of the following compound statements. a) p q b) p q Here we see that the corresponding truth tables for two statement p q

More information

Section 1.1 Propositional Logic. proposition : true = T (or 1) or false = F (or 0) (binary logic) the moon is made of green cheese

Section 1.1 Propositional Logic. proposition : true = T (or 1) or false = F (or 0) (binary logic) the moon is made of green cheese Section 1.1 Propositional Logic proposition : true = T (or 1) or false = F (or 0) (binary logic) the moon is made of green cheese go to town! X - imperative What time is it? X - interrogative propositional

More information

HW1 graded review form? HW2 released CSE 20 DISCRETE MATH. Fall

HW1 graded review form? HW2 released CSE 20 DISCRETE MATH. Fall CSE 20 HW1 graded review form? HW2 released DISCRETE MATH Fall 2017 http://cseweb.ucsd.edu/classes/fa17/cse20-ab/ Today's learning goals Translate sentences from English to propositional logic using appropriate

More information

Discrete Mathematical Structures. Chapter 1 The Foundation: Logic

Discrete Mathematical Structures. Chapter 1 The Foundation: Logic Discrete Mathematical Structures Chapter 1 he oundation: Logic 1 Lecture Overview 1.1 Propositional Logic 1.2 Propositional Equivalences 1.3 Quantifiers l l l l l Statement Logical Connectives Conjunction

More information

Introduction Logic Inference. Discrete Mathematics Andrei Bulatov

Introduction Logic Inference. Discrete Mathematics Andrei Bulatov Introduction Logic Inference Discrete Mathematics Andrei Bulatov Discrete Mathematics - Logic Inference 6-2 Previous Lecture Laws of logic Expressions for implication, biconditional, exclusive or Valid

More information

DISCRETE STRUCTURES WEEK5 LECTURE1

DISCRETE STRUCTURES WEEK5 LECTURE1 DISCRETE STRUCTURES WEEK5 LECTURE1 Let s get started with... Logic! Spring 2010 CPCS 222 - Discrete Structures 2 Logic Crucial for mathematical reasoning Important for program design Used for designing

More information

An Introduction to Logic 1.1 ~ 1.4 6/21/04 ~ 6/23/04

An Introduction to Logic 1.1 ~ 1.4 6/21/04 ~ 6/23/04 An Introduction to Logic 1.1 ~ 1.4 6/21/04 ~ 6/23/04 1 A Taste of Logic Logic puzzles (1) Knights and Knaves Knights: always tell the truth Knaves: always lie You encounter two people A and B. A says:

More information

1 The Foundations. 1.1 Logic. A proposition is a declarative sentence that is either true or false, but not both.

1 The Foundations. 1.1 Logic. A proposition is a declarative sentence that is either true or false, but not both. he oundations. Logic Propositions are building blocks of logic. A proposition is a declarative sentence that is either true or false, but not both. Example. Declarative sentences.. Ottawa is the capital

More information

Introduction. Applications of discrete mathematics:

Introduction. Applications of discrete mathematics: Introduction Applications of discrete mathematics: Formal Languages (computer languages) Compiler Design Data Structures Computability Automata Theory Algorithm Design Relational Database Theory Complexity

More information

Discrete Mathematics and Applications COT3100

Discrete Mathematics and Applications COT3100 Discrete Mathematics and Applications CO3100 Dr. Ungor Sources: Slides are based on Dr. G. Bebis material. uesday, January 7, 2014 oundations of Logic: Overview Propositional logic: (Sections 1.1-1.3)

More information

Numbers that are divisible by 2 are even. The above statement could also be written in other logically equivalent ways, such as:

Numbers that are divisible by 2 are even. The above statement could also be written in other logically equivalent ways, such as: 3.4 THE CONDITIONAL & BICONDITIONAL Definition. Any statement that can be put in the form If p, then q, where p and q are basic statements, is called a conditional statement and is written symbolically

More information

Sec$on Summary. Propositions Connectives. Truth Tables. Negation Conjunction Disjunction Implication; contrapositive, inverse, converse Biconditional

Sec$on Summary. Propositions Connectives. Truth Tables. Negation Conjunction Disjunction Implication; contrapositive, inverse, converse Biconditional Section 1.1 Sec$on Summary Propositions Connectives Negation Conjunction Disjunction Implication; contrapositive, inverse, converse Biconditional ruth ables 2 Proposi$ons A proposition is a declarative

More information

Propositional Logic. Spring Propositional Logic Spring / 32

Propositional Logic. Spring Propositional Logic Spring / 32 Propositional Logic Spring 2016 Propositional Logic Spring 2016 1 / 32 Introduction Learning Outcomes for this Presentation Learning Outcomes... At the conclusion of this session, we will Define the elements

More information

Section 1.1: Logical Form and Logical Equivalence

Section 1.1: Logical Form and Logical Equivalence Section 1.1: Logical Form and Logical Equivalence An argument is a sequence of statements aimed at demonstrating the truth of an assertion. The assertion at the end of an argument is called the conclusion,

More information

EECS 1028 M: Discrete Mathematics for Engineers

EECS 1028 M: Discrete Mathematics for Engineers EECS 1028 M: Discrete Mathematics for Engineers Suprakash Datta Office: LAS 3043 Course page: http://www.eecs.yorku.ca/course/1028 Also on Moodle S. Datta (York Univ.) EECS 1028 W 18 1 / 26 Why Study Logic?

More information

CS100: DISCRETE STRUCTURES. Lecture 5: Logic (Ch1)

CS100: DISCRETE STRUCTURES. Lecture 5: Logic (Ch1) CS100: DISCREE SRUCURES Lecture 5: Logic (Ch1) Lecture Overview 2 Statement Logical Connectives Conjunction Disjunction Propositions Conditional Bio-conditional Converse Inverse Contrapositive Laws of

More information

Logic as a Tool Chapter 1: Understanding Propositional Logic 1.1 Propositions and logical connectives. Truth tables and tautologies

Logic as a Tool Chapter 1: Understanding Propositional Logic 1.1 Propositions and logical connectives. Truth tables and tautologies Logic as a Tool Chapter 1: Understanding Propositional Logic 1.1 Propositions and logical connectives. Truth tables and tautologies Valentin Stockholm University September 2016 Propositions Proposition:

More information

A statement is a sentence that is definitely either true or false but not both.

A statement is a sentence that is definitely either true or false but not both. 5 Logic In this part of the course we consider logic. Logic is used in many places in computer science including digital circuit design, relational databases, automata theory and computability, and artificial

More information

Discrete Structures & Algorithms. Propositional Logic EECE 320 // UBC

Discrete Structures & Algorithms. Propositional Logic EECE 320 // UBC Discrete Structures & Algorithms Propositional Logic EECE 320 // UBC 1 Review of last lecture Pancake sorting A problem with many applications Bracketing (bounding a function) Proving bounds for pancake

More information

Discrete Mathematics

Discrete Mathematics Discrete Mathematics Discrete mathematics is devoted to the study of discrete or distinct unconnected objects. Classical mathematics deals with functions on real numbers. Real numbers form a continuous

More information

MAT2345 Discrete Math

MAT2345 Discrete Math Fall 2013 General Syllabus Schedule (note exam dates) Homework, Worksheets, Quizzes, and possibly Programs & Reports Academic Integrity Do Your Own Work Course Web Site: www.eiu.edu/~mathcs Course Overview

More information

Propositional Logic 1

Propositional Logic 1 Propositional Logic 1 Section Summary Propositions Connectives Negation Conjunction Disjunction Implication; contrapositive, inverse, converse Biconditional Truth Tables 2 Propositions A proposition is

More information

DISCRETE MATHEMATICS BA202

DISCRETE MATHEMATICS BA202 TOPIC 1 BASIC LOGIC This topic deals with propositional logic, logical connectives and truth tables and validity. Predicate logic, universal and existential quantification are discussed 1.1 PROPOSITION

More information

2/13/2012. Logic: Truth Tables. CS160 Rosen Chapter 1. Logic?

2/13/2012. Logic: Truth Tables. CS160 Rosen Chapter 1. Logic? Logic: Truth Tables CS160 Rosen Chapter 1 Logic? 1 What is logic? Logic is a truth-preserving system of inference Truth-preserving: If the initial statements are true, the inferred statements will be true

More information

ARTIFICIAL INTELLIGENCE

ARTIFICIAL INTELLIGENCE ARTIFICIAL INTELLIGENCE LECTURE # 03 Artificial Intelligence 2012 Lecture 03 Delivered By Zahid Iqbal 1 Review of Last Lecture Artificial Intelligence 2012 Lecture 03 Delivered By Zahid Iqbal 2 Today s

More information

Learning Goals of CS245 Logic and Computation

Learning Goals of CS245 Logic and Computation Learning Goals of CS245 Logic and Computation Alice Gao April 27, 2018 Contents 1 Propositional Logic 2 2 Predicate Logic 4 3 Program Verification 6 4 Undecidability 7 1 1 Propositional Logic Introduction

More information

Today s Topic: Propositional Logic

Today s Topic: Propositional Logic Today s Topic: Propositional Logic What is a proposition? Logical connectives and truth tables Translating between English and propositional logic Logic is the basis of all mathematical and analytical

More information

Chapter 1, Part I: Propositional Logic. With Question/Answer Animations

Chapter 1, Part I: Propositional Logic. With Question/Answer Animations Chapter 1, Part I: Propositional Logic With Question/Answer Animations Chapter Summary! Propositional Logic! The Language of Propositions! Applications! Logical Equivalences! Predicate Logic! The Language

More information

Propositional Logic. Fall () Propositional Logic Fall / 30

Propositional Logic. Fall () Propositional Logic Fall / 30 Propositional Logic Fall 2013 () Propositional Logic Fall 2013 1 / 30 1 Introduction Learning Outcomes for this Presentation 2 Definitions Statements Logical connectives Interpretations, contexts,... Logically

More information

Why Learning Logic? Logic. Propositional Logic. Compound Propositions

Why Learning Logic? Logic. Propositional Logic. Compound Propositions Logic Objectives Propositions and compound propositions Negation, conjunction, disjunction, and exclusive or Implication and biconditional Logic equivalence and satisfiability Application of propositional

More information

The statement calculus and logic

The statement calculus and logic Chapter 2 Contrariwise, continued Tweedledee, if it was so, it might be; and if it were so, it would be; but as it isn t, it ain t. That s logic. Lewis Carroll You will have encountered several languages

More information

3/29/2017. Logic. Propositions and logical operations. Main concepts: propositions truth values propositional variables logical operations

3/29/2017. Logic. Propositions and logical operations. Main concepts: propositions truth values propositional variables logical operations Logic Propositions and logical operations Main concepts: propositions truth values propositional variables logical operations 1 Propositions and logical operations A proposition is the most basic element

More information

Chapter 5: Section 5-1 Mathematical Logic

Chapter 5: Section 5-1 Mathematical Logic Chapter 5: Section 5-1 Mathematical Logic D. S. Malik Creighton University, Omaha, NE D. S. Malik Creighton University, Omaha, NE Chapter () 5: Section 5-1 Mathematical Logic 1 / 29 Mathematical Logic

More information

Chapter 4: Classical Propositional Semantics

Chapter 4: Classical Propositional Semantics Chapter 4: Classical Propositional Semantics Language : L {,,, }. Classical Semantics assumptions: TWO VALUES: there are only two logical values: truth (T) and false (F), and EXTENSIONALITY: the logical

More information

CSCE 222 Discrete Structures for Computing. Propositional Logic. Dr. Hyunyoung Lee. !!!!!! Based on slides by Andreas Klappenecker

CSCE 222 Discrete Structures for Computing. Propositional Logic. Dr. Hyunyoung Lee. !!!!!! Based on slides by Andreas Klappenecker CSCE 222 Discrete Structures for Computing Propositional Logic Dr. Hyunyoung Lee Based on slides by Andreas Klappenecker 1 Propositions A proposition is a declarative sentence that is either true or false

More information

Logic. Definition [1] A logic is a formal language that comes with rules for deducing the truth of one proposition from the truth of another.

Logic. Definition [1] A logic is a formal language that comes with rules for deducing the truth of one proposition from the truth of another. Math 0413 Appendix A.0 Logic Definition [1] A logic is a formal language that comes with rules for deducing the truth of one proposition from the truth of another. This type of logic is called propositional.

More information

The Foundations: Logic and Proofs. Part I

The Foundations: Logic and Proofs. Part I The Foundations: Logic and Proofs Part I Chapter Summary Propositional Logic n The Language of Propositions n Applications n Logical Equivalences Predicate Logic n The Language of Quantifiers n Logical

More information

Chapter 1, Section 1.1 Propositional Logic

Chapter 1, Section 1.1 Propositional Logic Discrete Structures Chapter 1, Section 1.1 Propositional Logic These class notes are based on material from our textbook, Discrete Mathematics and Its Applications, 6 th ed., by Kenneth H. Rosen, published

More information

AMTH140 Lecture 8. Symbolic Logic

AMTH140 Lecture 8. Symbolic Logic AMTH140 Lecture 8 Slide 1 Symbolic Logic March 10, 2006 Reading: Lecture Notes 6.2, 6.3; Epp 1.1, 1.2 Logical Connectives Let p and q denote propositions, then: 1. p q is conjunction of p and q, meaning

More information

Maryam Al-Towailb (KSU) Discrete Mathematics and Its Applications Math. Rules Math. of1101 Inference 1 / 13

Maryam Al-Towailb (KSU) Discrete Mathematics and Its Applications Math. Rules Math. of1101 Inference 1 / 13 Maryam Al-Towailb (KSU) Discrete Mathematics and Its Applications Math. Rules 151 - Math. of1101 Inference 1 / 13 Maryam Al-Towailb (KSU) Discrete Mathematics and Its Applications Math. Rules 151 - Math.

More information

Overview. 1. Introduction to Propositional Logic. 2. Operations on Propositions. 3. Truth Tables. 4. Translating Sentences into Logical Expressions

Overview. 1. Introduction to Propositional Logic. 2. Operations on Propositions. 3. Truth Tables. 4. Translating Sentences into Logical Expressions Note 01 Propositional Logic 1 / 10-1 Overview 1. Introduction to Propositional Logic 2. Operations on Propositions 3. Truth Tables 4. Translating Sentences into Logical Expressions 5. Preview: Propositional

More information

Propositional Logic Basics Propositional Equivalences Normal forms Boolean functions and digital circuits. Propositional Logic.

Propositional Logic Basics Propositional Equivalences Normal forms Boolean functions and digital circuits. Propositional Logic. Propositional Logic Winter 2012 Propositional Logic: Section 1.1 Proposition A proposition is a declarative sentence that is either true or false. Which ones of the following sentences are propositions?

More information

Logic and Truth Tables

Logic and Truth Tables Logic and Truth Tables What is a Truth Table? A truth table is a tool that helps you analyze statements or arguments in order to verify whether or not they are logical, or true. There are five basic operations

More information

Math Assignment 2 Solutions - Spring Jaimos F Skriletz Provide definitions for the following:

Math Assignment 2 Solutions - Spring Jaimos F Skriletz Provide definitions for the following: Math 124 - Assignment 2 Solutions - Spring 2009 - Jaimos F Skriletz 1 1. Provide definitions for the following: (a) A statement is a declarative sentence that is either true or false, but not both at the

More information

Proposition/Statement. Boolean Logic. Boolean variables. Logical operators: And. Logical operators: Not 9/3/13. Introduction to Logical Operators

Proposition/Statement. Boolean Logic. Boolean variables. Logical operators: And. Logical operators: Not 9/3/13. Introduction to Logical Operators Proposition/Statement Boolean Logic CS 231 Dianna Xu A proposition is either true or false but not both he sky is blue Lisa is a Math major x == y Not propositions: Are you Bob? x := 7 1 2 Boolean variables

More information

Introduction Propositional Logic

Introduction Propositional Logic Discrete Mathematics for CSE of KU Introduction Propositional Logic Instructor: Kangil Kim (CSE) E-mail: kikim01@konkuk.ac.kr Tel. : 02-450-3493 Room : New Milenium Bldg. 1103 Lab : New Engineering Bldg.

More information

Logic. Def. A Proposition is a statement that is either true or false.

Logic. Def. A Proposition is a statement that is either true or false. Logic Logic 1 Def. A Proposition is a statement that is either true or false. Examples: Which of the following are propositions? Statement Proposition (yes or no) If yes, then determine if it is true or

More information

Definition 2. Conjunction of p and q

Definition 2. Conjunction of p and q Proposition Propositional Logic CPSC 2070 Discrete Structures Rosen (6 th Ed.) 1.1, 1.2 A proposition is a statement that is either true or false, but not both. Clemson will defeat Georgia in football

More information

ANALYSIS EXERCISE 1 SOLUTIONS

ANALYSIS EXERCISE 1 SOLUTIONS ANALYSIS EXERCISE 1 SOLUTIONS 1. (a) Let B The main course will be beef. F The main course will be fish. P The vegetable will be peas. C The vegetable will be corn. The logical form of the argument is

More information

2/2/2018. CS 103 Discrete Structures. Chapter 1. Propositional Logic. Chapter 1.1. Propositional Logic

2/2/2018. CS 103 Discrete Structures. Chapter 1. Propositional Logic. Chapter 1.1. Propositional Logic CS 103 Discrete Structures Chapter 1 Propositional Logic Chapter 1.1 Propositional Logic 1 1.1 Propositional Logic Definition: A proposition :is a declarative sentence (that is, a sentence that declares

More information

Proofs. Joe Patten August 10, 2018

Proofs. Joe Patten August 10, 2018 Proofs Joe Patten August 10, 2018 1 Statements and Open Sentences 1.1 Statements A statement is a declarative sentence or assertion that is either true or false. They are often labelled with a capital

More information

Discrete Structures for Computer Science

Discrete Structures for Computer Science Discrete Structures for Computer Science William Garrison bill@cs.pitt.edu 6311 Sennott Square Lecture #2: Propositional Logic Based on materials developed by Dr. Adam Lee Today s Topic: Propositional

More information

Equivalence and Implication

Equivalence and Implication Equivalence and Alice E. Fischer CSCI 1166 Discrete Mathematics for Computing February 7 8, 2018 Alice E. Fischer Laws of Logic... 1/33 1 Logical Equivalence Contradictions and Tautologies 2 3 4 Necessary

More information

PS10.3 Logical implications

PS10.3 Logical implications Warmup: Construct truth tables for these compound statements: 1) p (q r) p q r p q r p (q r) PS10.3 Logical implications Lets check it out: We will be covering Implications, logical equivalence, converse,

More information

GEOMETRY. Chapter 2: LOGIC. Name: Teacher: Pd:

GEOMETRY. Chapter 2: LOGIC. Name: Teacher: Pd: GEOMERY Chapter 2: LOGIC Name: eacher: Pd: able of Contents DAY 1: SWBA: Identify, write and analyze the different types of logical statements. Pgs: 2-8 Homework: Pgs 6 8 (EVEN ONLY) DAY 2: SWBA: Write

More information

We last time we began introducing equivalency laws.

We last time we began introducing equivalency laws. Monday, January 14 MAD2104 Discrete Math 1 Course website: www/mathfsuedu/~wooland/mad2104 Today we will continue in Course Notes Chapter 22 We last time we began introducing equivalency laws Today we

More information

Logic and Proofs. Jan COT3100: Applications of Discrete Structures Jan 2007

Logic and Proofs. Jan COT3100: Applications of Discrete Structures Jan 2007 COT3100: Propositional Equivalences 1 Logic and Proofs Jan 2007 COT3100: Propositional Equivalences 2 1 Translating from Natural Languages EXAMPLE. Translate the following sentence into a logical expression:

More information

Logic. Propositional Logic: Syntax

Logic. Propositional Logic: Syntax Logic Propositional Logic: Syntax Logic is a tool for formalizing reasoning. There are lots of different logics: probabilistic logic: for reasoning about probability temporal logic: for reasoning about

More information

Boolean Logic. CS 231 Dianna Xu

Boolean Logic. CS 231 Dianna Xu Boolean Logic CS 231 Dianna Xu 1 Proposition/Statement A proposition is either true or false but not both The sky is blue Lisa is a Math major x == y Not propositions: Are you Bob? x := 7 2 Boolean variables

More information

Announcements. CS311H: Discrete Mathematics. Propositional Logic II. Inverse of an Implication. Converse of a Implication

Announcements. CS311H: Discrete Mathematics. Propositional Logic II. Inverse of an Implication. Converse of a Implication Announcements CS311H: Discrete Mathematics Propositional Logic II Instructor: Işıl Dillig First homework assignment out today! Due in one week, i.e., before lecture next Wed 09/13 Remember: Due before

More information

Chapter 1: The Logic of Compound Statements. January 7, 2008

Chapter 1: The Logic of Compound Statements. January 7, 2008 Chapter 1: The Logic of Compound Statements January 7, 2008 Outline 1 1.1 Logical Form and Logical Equivalence 2 1.2 Conditional Statements 3 1.3 Valid and Invalid Arguments Central notion of deductive

More information

15414/614 Optional Lecture 1: Propositional Logic

15414/614 Optional Lecture 1: Propositional Logic 15414/614 Optional Lecture 1: Propositional Logic Qinsi Wang Logic is the study of information encoded in the form of logical sentences. We use the language of Logic to state observations, to define concepts,

More information

n logical not (negation) n logical or (disjunction) n logical and (conjunction) n logical exclusive or n logical implication (conditional)

n logical not (negation) n logical or (disjunction) n logical and (conjunction) n logical exclusive or n logical implication (conditional) Discrete Math Review Discrete Math Review (Rosen, Chapter 1.1 1.6) TOPICS Propositional Logic Logical Operators Truth Tables Implication Logical Equivalence Inference Rules What you should know about propositional

More information

Propositional Languages

Propositional Languages Propositional Logic Propositional Languages A propositional signature is a set/sequence of primitive symbols, called proposition constants. Given a propositional signature, a propositional sentence is

More information

Lecture 02: Propositional Logic

Lecture 02: Propositional Logic Lecture 02: Propositional Logic CSCI 358 Discrete Mathematics, Spring 2016 Hua Wang, Ph.D. Department of Electrical Engineering and Computer Science January 19, 2015 Propositional logic Propositional logic

More information

AI Principles, Semester 2, Week 2, Lecture 5 Propositional Logic and Predicate Logic

AI Principles, Semester 2, Week 2, Lecture 5 Propositional Logic and Predicate Logic AI Principles, Semester 2, Week 2, Lecture 5 Propositional Logic and Predicate Logic Propositional logic Logical connectives Rules for wffs Truth tables for the connectives Using Truth Tables to evaluate

More information

PHI Propositional Logic Lecture 2. Truth Tables

PHI Propositional Logic Lecture 2. Truth Tables PHI 103 - Propositional Logic Lecture 2 ruth ables ruth ables Part 1 - ruth unctions for Logical Operators ruth unction - the truth-value of any compound proposition determined solely by the truth-value

More information

Announcements. CS243: Discrete Structures. Propositional Logic II. Review. Operator Precedence. Operator Precedence, cont. Operator Precedence Example

Announcements. CS243: Discrete Structures. Propositional Logic II. Review. Operator Precedence. Operator Precedence, cont. Operator Precedence Example Announcements CS243: Discrete Structures Propositional Logic II Işıl Dillig First homework assignment out today! Due in one week, i.e., before lecture next Tuesday 09/11 Weilin s Tuesday office hours are

More information

MACM 101 Discrete Mathematics I. Exercises on Propositional Logic. Due: Tuesday, September 29th (at the beginning of the class)

MACM 101 Discrete Mathematics I. Exercises on Propositional Logic. Due: Tuesday, September 29th (at the beginning of the class) MACM 101 Discrete Mathematics I Exercises on Propositional Logic. Due: Tuesday, September 29th (at the beginning of the class) SOLUTIONS 1. Construct a truth table for the following compound proposition:

More information

10/5/2012. Logic? What is logic? Propositional Logic. Propositional Logic (Rosen, Chapter ) Logic is a truth-preserving system of inference

10/5/2012. Logic? What is logic? Propositional Logic. Propositional Logic (Rosen, Chapter ) Logic is a truth-preserving system of inference Logic? Propositional Logic (Rosen, Chapter 1.1 1.3) TOPICS Propositional Logic Truth Tables Implication Logical Proofs 10/1/12 CS160 Fall Semester 2012 2 What is logic? Logic is a truth-preserving system

More information

CSE 240 Logic and Discrete Mathematics

CSE 240 Logic and Discrete Mathematics CSE 240 Logic and Discrete Mathematics Instructor: odd Sproull Department of Computer Science and Engineering Washington University in St. Louis 1Extensible - CSE 240 Logic Networking and Discrete Platform

More information

LOGIC CONNECTIVES. Students who have an ACT score of at least 30 OR a GPA of at least 3.5 can receive a college scholarship.

LOGIC CONNECTIVES. Students who have an ACT score of at least 30 OR a GPA of at least 3.5 can receive a college scholarship. LOGIC In mathematical and everyday English language, we frequently use logic to express our thoughts verbally and in writing. We also use logic in numerous other areas such as computer coding, probability,

More information

ECOM Discrete Mathematics

ECOM Discrete Mathematics ECOM 2311- Discrete Mathematics Chapter # 1 : The Foundations: Logic and Proofs Fall, 2013/2014 ECOM 2311- Discrete Mathematics - Ch.1 Dr. Musbah Shaat 1 / 85 Outline 1 Propositional Logic 2 Propositional

More information

Logic and Proofs. (A brief summary)

Logic and Proofs. (A brief summary) Logic and Proofs (A brief summary) Why Study Logic: To learn to prove claims/statements rigorously To be able to judge better the soundness and consistency of (others ) arguments To gain the foundations

More information

1.1 Language and Logic

1.1 Language and Logic c Oksana Shatalov, Fall 2017 1 1.1 Language and Logic Mathematical Statements DEFINITION 1. A proposition is any declarative sentence (i.e. it has both a subject and a verb) that is either true or false,

More information

Propositional Calculus. Problems. Propositional Calculus 3&4. 1&2 Propositional Calculus. Johnson will leave the cabinet, and we ll lose the election.

Propositional Calculus. Problems. Propositional Calculus 3&4. 1&2 Propositional Calculus. Johnson will leave the cabinet, and we ll lose the election. 1&2 Propositional Calculus Propositional Calculus Problems Jim Woodcock University of York October 2008 1. Let p be it s cold and let q be it s raining. Give a simple verbal sentence which describes each

More information

Discrete Mathematics and Its Applications

Discrete Mathematics and Its Applications Discrete Mathematics and Its Applications Lecture 1: Proposition logic MING GAO DASE @ ECNU (for course related communications) mgao@dase.ecnu.edu.cn Sep. 12, 2017 Outline 1 Propositions 2 Connectives

More information

1.1 Language and Logic

1.1 Language and Logic c Oksana Shatalov, Spring 2018 1 1.1 Language and Logic Mathematical Statements DEFINITION 1. A proposition is any declarative sentence (i.e. it has both a subject and a verb) that is either true or false,

More information

CSCI.6962/4962 Software Verification Fundamental Proof Methods in Computer Science (Arkoudas and Musser) Chapter p. 1/33

CSCI.6962/4962 Software Verification Fundamental Proof Methods in Computer Science (Arkoudas and Musser) Chapter p. 1/33 CSCI.6962/4962 Software Verification Fundamental Proof Methods in Computer Science (Arkoudas and Musser) Chapter 4.1-4.8 p. 1/33 CSCI.6962/4962 Software Verification Fundamental Proof Methods in Computer

More information

CSE 20 DISCRETE MATH. Fall

CSE 20 DISCRETE MATH. Fall CSE 20 DISCRETE MATH Fall 2017 http://cseweb.ucsd.edu/classes/fa17/cse20-ab/ Today's learning goals Describe and use algorithms for integer operations based on their expansions Relate algorithms for integer

More information

Logic Overview, I. and T T T T F F F T F F F F

Logic Overview, I. and T T T T F F F T F F F F Logic Overview, I DEFINITIONS A statement (proposition) is a declarative sentence that can be assigned a truth value T or F, but not both. Statements are denoted by letters p, q, r, s,... The 5 basic logical

More information

CS1021. Why logic? Logic about inference or argument. Start from assumptions or axioms. Make deductions according to rules of reasoning.

CS1021. Why logic? Logic about inference or argument. Start from assumptions or axioms. Make deductions according to rules of reasoning. 3: Logic Why logic? Logic about inference or argument Start from assumptions or axioms Make deductions according to rules of reasoning Logic 3-1 Why logic? (continued) If I don t buy a lottery ticket on

More information

Logic: Propositional Logic (Part I)

Logic: Propositional Logic (Part I) Logic: Propositional Logic (Part I) Alessandro Artale Free University of Bozen-Bolzano Faculty of Computer Science http://www.inf.unibz.it/ artale Descrete Mathematics and Logic BSc course Thanks to Prof.

More information

Propositional logic ( ): Review from Mat 1348

Propositional logic ( ): Review from Mat 1348 CSI 2101 / Winter 2008: Discrete Structures. Propositional logic ( 1.1-1.2): Review from Mat 1348 Dr. Nejib Zaguia - Winter 2008 1 Propositional logic: Review Mathematical Logic is a tool for working with

More information

Symbolic Logic 3. For an inference to be deductively valid it is impossible for the conclusion to be false if the premises are true.

Symbolic Logic 3. For an inference to be deductively valid it is impossible for the conclusion to be false if the premises are true. Symbolic Logic 3 Testing deductive validity with truth tables For an inference to be deductively valid it is impossible for the conclusion to be false if the premises are true. So, given that truth tables

More information

Chapter 1: Formal Logic

Chapter 1: Formal Logic Chapter 1: Formal Logic Dr. Fang (Daisy) Tang ftang@cpp.edu www.cpp.edu/~ftang/ CS 130 Discrete Structures Logic: The Foundation of Reasoning Definition: the foundation for the organized, careful method

More information

Propositional Equivalence

Propositional Equivalence Propositional Equivalence Tautologies and contradictions A compound proposition that is always true, regardless of the truth values of the individual propositions involved, is called a tautology. Example:

More information

Packet #1: Logic & Proofs. Applied Discrete Mathematics

Packet #1: Logic & Proofs. Applied Discrete Mathematics Packet #1: Logic & Proofs Applied Discrete Mathematics Table of Contents Course Objectives Page 2 Propositional Calculus Information Pages 3-13 Course Objectives At the conclusion of this course, you should

More information