CS 173: Discrete Mathematical Structures, Spring 2008 Homework 1 Solutions
|
|
- Spencer Webb
- 5 years ago
- Views:
Transcription
1 CS 173: Discrete Mathematical Structures, Spring 2008 Homework 1 Solutions 1. [10 points] Translate the following sentences into propositional logic, making the meaning of your propositional variables clear, and then create a truth table for each sentence. See page 11 of the textbook for some examples of translating English sentences into propositional logic. Normal English is somewhat vague about the meaning of or. As a result, the sentences in both parts of this problem could be translated using either the inclusive or ( ) or the exclusive or ( ) operator. We ve shown one option, but the other is also worth full credit. Be aware that in mathematical English (e.g. proofs), or should always be read as inclusive or. (a) Either the Chicago White Sox pitching improves and they continue to hit well or the Minnesota Twins will win the division. Let p, q, and r represent the Chicago White Sox pitching improves, the White Sox continue to hit well, and the Minnesota Twins will win the division respectively. Then the above can be written as (p q) r. The truth table for this sentence is: p q r (p q) r T T T F T T F T T F T T T F F F F T T T F T F F F F T T F F F F (b) Discrete mathematics is interesting and has many useful applications or the students will not be happy. Let p, q, and r represent Discrete mathematics is interesting, Discrete mathematics has many useful applications, and the students will be happy respectively. Then the above can be written as (p q) r. The truth table for this sentence is: p q r (p q) r T T T T T T F T T F T F T F F T F T T F F T F T F F T F F F F T 1
2 2. [4 points] Use a truth table to show that the following logical equivalence is correct ((p p) q) (p q) p q p p (p p) q ((p p) q) (p q) T T T F T T T F T T F F F T F T F F F F F F T T 3. [10 points] In the following exercises, use the logical equivalences given on pages 24 and 25 of the textbook (in Tables 6 through 8) to show that: (a) ( p (q r)) (q (p r)) Notice that there is typically more than one reasonable sequence of equivalences for such a problem, so your answer may not exactly match this one. ( p (q r)) ( p ( q r)) ( p ( q r)) (p ( q r)) (double negation law) (( q r) p) (commutative law) ( q (r p)) (associative law) ( q (p r)) (commutative law) (q (p r)) (b) (p q) (p q) is a contradiction (i.e. always false). (p q) (p q) (p q) (p q) (p q) ( p q) (De Morgan s law) p (q ( p q)) (associative law) p (q ( q p)) (commutative law) p ((q q) p) (associative law) p (F p) (negation law) p ( p F ) (commutative law) p F (domination law) F (domination law) 2
3 (c) (4 points) (p q) ( p r) (q r) is a tautology (i.e. always true) Notice that square brackets are used here simply as a variation of parentheses, so that complex sets of parentheses are easier to read. (p q) ( p r) (q r) [(p q) ( p r)] (q r) (from table 7) [ (p q) ( p r)] (q r) (De Morgan s law) [( p q) ( p r)] (q r) (De Morgan s law) [( p q) ( p r)] (q r) (De Morgan s law) [( p q) (p r)] (q r) (double negation law) We now need to shuffle the terms around, so as to group together the q and q terms, and also the p and p terms. [( p q) (p r)] (q r) ( p q) [(p r) (q r)] (associative law) ( p q) [(p r) (r q)] (commutative law) ( p q) [((p r) r) q)] (associative law) ( p q) [q ((p r) r))] (commutative law) [( p q) q] [(p r) r] (associative law) Now we can simplify each half of the expression: [( p q) q] [(p r) r] [q ( p q)] [r (p r)] (commutative law) [(q p) (q q)] [(r p) (r r)] (distributive law) [(q p) T ] [(r p) T ] (negation law) (q p) (r p) (identity law) And finally merge them: (q p) (r p) q [ p (r p)] (associative law) q [ p (p r)] (commutative law) q [( p p) r] (associative law) q (T r) (negation law) q (r T ) (commutative law) q T (domination law) T (domination law) 3
4 4. [5 points] Assume that there are only two kinds of people, a person is either authentic or a charlatan. A person is authentic if and only if every statement they make is true. A person is a charlatan if and only if every statement they make is false. Suppose you meet Augustus De Morgan and Charles Babbage in class one day and they say the following: Babbage: Both De Morgan and I are authentic. De Morgan: Babbage is a charlatan What kind of people are De Morgan and Babbage? Justify your answer. Solution 1: De Morgan is authentic, while Babbage is a charlatan (no offense intended to Babbage). If Babbage is authentic, then his statement is true both he and De Morgan are authentic. However, if De Morgan is authentic, then his statement is true Babbage is a charlatan, which creates a contradiction. Thus, Babbage must be a charlatan. This means that De Morgan s statement is true, so De Morgan is authentic. Solution 2: First we model the possible statements from the problem definition: p = Babbage is authentic. q = Babbage is a charlatan. r = De Morgan is a authentic. s = De Morgan is a charlatan. There are only two kinds of people (a person is either authentic, or a charlatan, but not both). Thus we have: p q r s This means we can forget about q and s, and work uniquely with p and r (we could alternatively work with p and s, or q and s). We know that an authentic person always makes true statements. We can model De Morgan: Babbage is a charlatan as: r p, that is, r p. This is saying that if r is true, De Morgan is authentic, whatever De Morgan says is true. In this case, De Morgan says Babbage is not authentic, a charlatan, or p. If r is false (De Morgan is a charlatan), then p needs to be false too, that is, Babbage is authentic. Similarly, we model Babbage: Both De Morgan and I are authentic with: p (p r) Using r p in p (p r): 4
5 p (p p) Using a negation law in the previous expression: p F Since r p, we have that r T. We conclude that De Morgan is authentic (p), and Babbage a charlatan ( r). 5. [5 points] (a) State the negation of the statement I have overslept or the building is on fire, using demorgan s laws to move the negation from the whole thing onto the two component statements. By De Morgan s laws, (p q) p q. Let p and q represent the statements I have overslept and the building is on fire respectively. Then the negation of the statement I have overslept or the building is on fire is I have not overslept and the building is not on fire. (b) Using your result from part (a), write the negation, contrapositive, converse and inverse of the following statement (see page 8 of the textbook for a related example). If I have overslept or the building is on fire, then the class will be canceled. Let r represent the statement the class is canceled, and define p and q as above. Then ((p q) r) (p q) r, so the negation of the statement is I have overslept or the building is on fire, and the class will not be canceled. The contrapositive of the statement is r ( p q): If the class is not canceled, then I have not overslept and the building is not on fire. The converse of the statement is r (p q): If the class is canceled, then I have overslept or the building is on fire. The inverse of the statement is ( p q) r: If I have not overslept and the building is not on fire, then the class will not be canceled. 5
6 6. [16 points] The late 19th century philosopher Charles Peirce (rhymes with hearse, not fierce ) wrote about a set of logically dual operators and, in his writings, coined the term Ampheck to describe them. The two most common Ampheck operators, the Peirce arrow (written or or by different people) and the Sheffer stroke (written or or by different people), are defined by the following truth table: p q p q p q T T F F T F T F F T T F F F T T (a) The set of operators {,, } is functionally complete, which means that every logical statement can be expressed using only these three operators. Is the smaller set of operators {, } also functionally complete? Explain why or why not. By De Morgan s laws, p q (p q), so every logical statement using the operator can be rewritten in terms of the and operators. Since every logical statement can be expressed in terms of the,, and operators, this implies that every logical statement can be expressed in terms of the and operators, and so {, } is functionally complete. (b) Express p using only the Sheffer stroke operation. p is true if and only if p is false. We can see from the truth table that when q is true, p q is true if and only if p is false. Thus, p can be expressed as p T. Alternatively, p p is equivalent to p p p p q T F F F T T (c) Express p q using only the Sheffer stroke operation. Justify your answer (e.g. using a truth table). p q (p T ) (q T ) p q T T T T T F T T F T T T F F F F Alternatively, observe from the table that p q (p q). By De Morgan s laws, (p q) p q, so p q p q. Replacing p with its definition in terms of the operator yields the expression (p T ) (q T ). Since p T p p p, another equivalent formula is (p p) (q q). 6
7 (d) Explain why the set of operators { } is functionally complete. In parts b and c, we showed that the and operators can be expressed in terms of the operator, so any statement that can be expressed in terms of those two operators can be expressed in terms of the operator. In part a, we showed that the set of operators {, } are sufficient to express any statement, so the set of the operator { } is also sufficient to express any statement, and thus is functionally complete. (e) (4 point bonus) Express the Sheffer stroke operation p q using only the Peirce arrow operation. Explain why the set of operators { } is functionally complete. p q ((p F ) (q F )) F p q T T F F T F T T F T T T F F T T Alternatively, observe from the table that p q (p q). By De Morgan s laws, (p q) p q, so p q p q. Looking again at the table, we see that p F p. Recall that p q (p q). Then we can see that (p q) ( p q), and rewriting the operator results in the expression ((p F ) (q F )) F as equivalent to p q. Notice that p F p p p. So, if you want to remove the literal use of F from the above formula, you can use the identity p F p p. to convert it to [(p p) (q q)] [(p p) (q q)] So, any statement that can be expressed with the can also be expressed with the operator. So, since { } is functionally complete, { } is also functionally complete. 7
ANS: If you are in Kwangju then you are in South Korea but not in Seoul.
Math 15 - Spring 2017 - Homework 1.1 and 1.2 Solutions 1. (1.1#1) Let the following statements be given. p = There is water in the cylinders. q = The head gasket is blown. r = The car will start. (a) Translate
More informationCSC 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 informationA 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 informationCompound 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 informationIntroduction to Decision Sciences Lecture 2
Introduction to Decision Sciences Lecture 2 Andrew Nobel August 24, 2017 Compound Proposition A compound proposition is a combination of propositions using the basic operations. For example (p q) ( p)
More information2.2: 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 informationLecture 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 informationMath.3336: Discrete Mathematics. Propositional Equivalences
Math.3336: Discrete Mathematics Propositional Equivalences Instructor: Dr. Blerina Xhabli Department of Mathematics, University of Houston https://www.math.uh.edu/ blerina Email: blerina@math.uh.edu Fall
More information2/2/2018. 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 informationWhat 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 informationCHAPTER 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 informationHomework 4 Solutions
Homework 4 Solutions ECS 20 (Fall 14) Patrice Koehl koehl@cs.ucdavis.edu November 1, 2017 Exercise 1 Let n be an integer. Give a direct proof, an indirect proof, and a proof by contradiction of the statement
More informationEECS 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 informationSection 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 informationAnnouncements. 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 informationLogical Operators. Conjunction Disjunction Negation Exclusive Or Implication Biconditional
Logical Operators Conjunction Disjunction Negation Exclusive Or Implication Biconditional 1 Statement meaning p q p implies q if p, then q if p, q when p, q whenever p, q q if p q when p q whenever p p
More informationChapter 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 informationHomework assignment 1: Solutions
Math 240: Discrete Structures I Due 4:30pm Friday 29 September 2017. McGill University, Fall 2017 Hand in to the mailbox at Burnside 1005. Homework assignment 1: Solutions Discussing the assignment with
More information2 Truth Tables, Equivalences and the Contrapositive
2 Truth Tables, Equivalences and the Contrapositive 12 2 Truth Tables, Equivalences and the Contrapositive 2.1 Truth Tables In a mathematical system, true and false statements are the statements of the
More informationCISC-102 Winter 2016 Lecture 17
CISC-102 Winter 2016 Lecture 17 Logic and Propositional Calculus Propositional logic was eventually refined using symbolic logic. The 17th/18th century philosopher Gottfried Leibniz (an inventor of calculus)
More informationRecitation Week 3. Taylor Spangler. January 23, 2012
Recitation Week 3 Taylor Spangler January 23, 2012 Questions about Piazza, L A TEX or lecture? Questions on the homework? (Skipped in Recitation) Let s start by looking at section 1.1, problem 15 on page
More informationChapter 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 informationSection 3.1 Statements, Negations, and Quantified Statements
Section 3.1 Statements, Negations, and Quantified Statements Objectives 1. Identify English sentences that are statements. 2. Express statements using symbols. 3. Form the negation of a statement 4. Express
More informationANALYSIS 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 informationLogic of Sentences (Propositional Logic) is interested only in true or false statements; does not go inside.
You are a mathematician if 1.1 Overview you say to a car dealer, I ll take the red car or the blue one, but then you feel the need to add, but not both. --- 1. Logic and Mathematical Notation (not in the
More informationCSCI Homework Set 1 Due: September 11, 2018 at the beginning of class
CSCI 3310 - Homework Set 1 Due: September 11, 2018 at the beginning of class ANSWERS Please write your name and student ID number clearly at the top of your homework. If you have multiple pages, please
More informationSolutions to Sample Problems for Midterm
Solutions to Sample Problems for Midterm Problem 1. The dual of a proposition is defined for which contains only,,. It is For a compound proposition that only uses,, as operators, we obtained the dual
More informationChapter 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 informationIntroduction to Sets and Logic (MATH 1190)
Introduction to Sets Logic () Instructor: Email: shenlili@yorku.ca Department of Mathematics Statistics York University Sept 18, 2014 Outline 1 2 Tautologies Definition A tautology is a compound proposition
More informationProf. Girardi Exam 1 Math 300 MARK BOX
NAME: Prof. Girardi 09.27.11 Exam 1 Math 300 problem MARK BOX points 1 40 2 5 3 10 4 5 5 10 6 10 7 5 8 5 9 8 10 2 total 100 Problem Inspiration (1) Quiz 1 (2) Exam 1 all 10 Number 3 (3) Homework and Study
More information2. 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 informationDefinition 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 informationChapter 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 informationProving Things. Why prove things? Proof by Substitution, within Logic. Rules of Inference: applying Logic. Using Assumptions.
1 Proving Things Why prove things? Proof by Substitution, within Logic Rules of Inference: applying Logic Using Assumptions Proof Strategies 2 Why Proofs? Knowledge is power. Where do we get it? direct
More informationPropositional 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 informationSection 2.3: Statements Containing Multiple Quantifiers
Section 2.3: Statements Containing Multiple Quantifiers In this section, we consider statements such as there is a person in this company who is in charge of all the paperwork where more than one quantifier
More informationPHIL12A Section answers, 16 February 2011
PHIL12A Section answers, 16 February 2011 Julian Jonker 1 How much do you know? 1. Show that the following sentences are equivalent. (a) (Ex 4.16) A B A and A B A B (A B) A A B T T T T T T T T T T T F
More information1.3 Propositional Equivalences
1 1.3 Propositional Equivalences The replacement of a statement with another statement with the same truth is an important step often used in Mathematical arguments. Due to this methods that produce propositions
More informationTHE LOGIC OF COMPOUND STATEMENTS
THE LOGIC OF COMPOUND STATEMENTS All dogs have four legs. All tables have four legs. Therefore, all dogs are tables LOGIC Logic is a science of the necessary laws of thought, without which no employment
More informationCSE 311: Foundations of Computing. Lecture 2: More Logic, Equivalence & Digital Circuits
CSE 311: Foundations of Computing Lecture 2: More Logic, Equivalence & Digital Circuits Last class: Some Connectives & Truth Tables Negation (not) p p T F F T Disjunction (or) p q p q T T T T F T F T T
More informationLING 106. Knowledge of Meaning Lecture 3-1 Yimei Xiang Feb 6, Propositional logic
LING 106. Knowledge of Meaning Lecture 3-1 Yimei Xiang Feb 6, 2016 Propositional logic 1 Vocabulary of propositional logic Vocabulary (1) a. Propositional letters: p, q, r, s, t, p 1, q 1,..., p 2, q 2,...
More informationBasic Logic and Proof Techniques
Chapter 3 Basic Logic and Proof Techniques Now that we have introduced a number of mathematical objects to study and have a few proof techniques at our disposal, we pause to look a little more closely
More informationPropositional Logic. Yimei Xiang 11 February format strictly follow the laws and never skip any step.
Propositional Logic Yimei Xiang yxiang@fas.harvard.edu 11 February 2014 1 Review Recursive definition Set up the basis Generate new members with rules Exclude the rest Subsets vs. proper subsets Sets of
More informationMath 13, Spring 2013, Lecture B: Midterm
Math 13, Spring 2013, Lecture B: Midterm Name Signature UCI ID # E-mail address Each numbered problem is worth 12 points, for a total of 84 points. Present your work, especially proofs, as clearly as possible.
More informationMidterm Exam Solution
Midterm Exam Solution Name PID Honor Code Pledge: I certify that I am aware of the Honor Code in effect in this course and observed the Honor Code in the completion of this exam. Signature Notes: 1. This
More informationLecture 7. Logic. Section1: Statement Logic.
Ling 726: Mathematical Linguistics, Logic, Section : Statement Logic V. Borschev and B. Partee, October 5, 26 p. Lecture 7. Logic. Section: Statement Logic.. Statement Logic..... Goals..... Syntax of Statement
More informationPropositional 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 informationConjunction: p q is true if both p, q are true, and false if at least one of p, q is false. The truth table for conjunction is as follows.
Chapter 1 Logic 1.1 Introduction and Definitions Definitions. A sentence (statement, proposition) is an utterance (that is, a string of characters) which is either true (T) or false (F). A predicate is
More informationCS1021. 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 information1.1 Statements and Compound Statements
Chapter 1 Propositional Logic 1.1 Statements and Compound Statements A statement or proposition is an assertion which is either true or false, though you may not know which. That is, a statement is something
More informationBoolean 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 information3/29/2017. 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 informationAnnouncement. Homework 1
Announcement I made a few small changes to the course calendar No class on Wed eb 27 th, watch the video lecture Quiz 8 will take place on Monday April 15 th We will submit assignments using Gradescope
More informationChapter 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 informationPROBLEM SET 3: PROOF TECHNIQUES
PROBLEM SET 3: PROOF TECHNIQUES CS 198-087: INTRODUCTION TO MATHEMATICAL THINKING UC BERKELEY EECS FALL 2018 This homework is due on Monday, September 24th, at 6:30PM, on Gradescope. As usual, this homework
More informationMat 243 Exam 1 Review
OBJECTIVES (Review problems: on next page) 1.1 Distinguish between propositions and non-propositions. Know the truth tables (i.e., the definitions) of the logical operators,,,, and Write truth tables for
More informationProblem 1: Suppose A, B, C and D are finite sets such that A B = C D and C = D. Prove or disprove: A = B.
Department of Computer Science University at Albany, State University of New York Solutions to Sample Discrete Mathematics Examination III (Spring 2007) Problem 1: Suppose A, B, C and D are finite sets
More information1.1 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 informationPreparing for the CS 173 (A) Fall 2018 Midterm 1
Preparing for the CS 173 (A) Fall 2018 Midterm 1 1 Basic information Midterm 1 is scheduled from 7:15-8:30 PM. We recommend you arrive early so that you can start exactly at 7:15. Exams will be collected
More informationProposition/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 information2/13/2012. 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 informationTHE LOGIC OF COMPOUND STATEMENTS
CHAPTER 2 THE LOGIC OF COMPOUND STATEMENTS Copyright Cengage Learning. All rights reserved. SECTION 2.1 Logical Form and Logical Equivalence Copyright Cengage Learning. All rights reserved. Logical Form
More informationTruth-Functional Logic
Truth-Functional Logic Syntax Every atomic sentence (A, B, C, ) is a sentence and are sentences With ϕ a sentence, the negation ϕ is a sentence With ϕ and ψ sentences, the conjunction ϕ ψ is a sentence
More information2/18/14. What is logic? Proposi0onal Logic. Logic? Propositional Logic, Truth Tables, and Predicate Logic (Rosen, Sections 1.1, 1.2, 1.
Logic? Propositional Logic, Truth Tables, and Predicate Logic (Rosen, Sections 1.1, 1.2, 1.3) TOPICS Propositional Logic Logical Operations Equivalences Predicate Logic CS160 - Spring Semester 2014 2 What
More informationPropositional 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 informationHOMEWORK 1: SOLUTIONS - MATH 215 INSTRUCTOR: George Voutsadakis
HOMEWORK 1: SOLUTIONS - MATH 215 INSTRUCTOR: George Voutsadakis Problem 1 Make truth tables for the propositional forms (P Q) (P R) and (P Q) (R S). Solution: P Q R P Q P R (P Q) (P R) F F F F F F F F
More informationSolutions to Exercises (Sections )
s to Exercises (Sections 1.1-1.10) Section 1.1 Exercise 1.1.1: Identifying propositions (a) Have a nice day. : Command, not a proposition. (b) The soup is cold. : Proposition. Negation: The soup is not
More informationDiscrete 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 informationCSE 311: Foundations of Computing. Lecture 3: Digital Circuits & Equivalence
CSE 311: Foundations of Computing Lecture 3: Digital Circuits & Equivalence Homework #1 You should have received An e-mail from [cse311a/cse311b] with information pointing you to look at Canvas to submit
More informationSample Problems for all sections of CMSC250, Midterm 1 Fall 2014
Sample Problems for all sections of CMSC250, Midterm 1 Fall 2014 1. Translate each of the following English sentences into formal statements using the logical operators (,,,,, and ). You may also use mathematical
More informationMathematical Logic Part One
Mathematical Logic Part One Question: How do we formalize the definitions and reasoning we use in our proofs? Where We're Going Propositional Logic (oday) Basic logical connectives. ruth tables. Logical
More informationSec 3.3 The Conditional & Circuits
Sec 3.3 The Conditional & Circuits Conditional statement: connective if... then. a compound statement that uses the Conditional statements are also known as implications, and can be written as: p q (pronounced
More informationCS1800 Discrete Structures Spring 2018 February CS1800 Discrete Structures Midterm Version A
CS1800 Discrete Structures Spring 2018 February 2018 CS1800 Discrete Structures Midterm Version A Instructions: 1. The exam is closed book and closed notes. You may not use a calculator or any other electronic
More informationSection 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 information10/5/2012. 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 informationhttps://vu5.sfc.keio.ac.jp/slide/
1 FUNDAMENTALS OF LOGIC NO.3 NORMAL FORMS Tatsuya Hagino hagino@sfc.keio.ac.jp lecture URL https://vu5.sfc.keio.ac.jp/slide/ 2 So Far What is Logic? mathematical logic symbolic logic Proposition A statement
More information3.2: Compound Statements and Connective Notes
3.2: Compound Statements and Connective Notes 1. Express compound statements in symbolic form. _Simple_ statements convey one idea with no connecting words. _Compound_ statements combine two or more simple
More informationThe Logic of Compound Statements cont.
The Logic of Compound Statements cont. CSE 215, Computer Science 1, Fall 2011 Stony Brook University http://www.cs.stonybrook.edu/~cse215 Refresh from last time: Logical Equivalences Commutativity of :
More informationTautologies, Contradictions, and Contingencies
Section 1.3 Tautologies, Contradictions, and Contingencies A tautology is a proposition which is always true. Example: p p A contradiction is a proposition which is always false. Example: p p A contingency
More informationComputer Science 280 Spring 2002 Homework 2 Solutions by Omar Nayeem
Computer Science 280 Spring 2002 Homework 2 Solutions by Omar Nayeem Part A 1. (a) Some dog does not have his day. (b) Some action has no equal and opposite reaction. (c) Some golfer will never be eated
More informationChapter 1 Elementary Logic
2017-2018 Chapter 1 Elementary Logic The study of logic is the study of the principles and methods used in distinguishing valid arguments from those that are not valid. The aim of this chapter is to help
More informationAnnouncements. 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 informationHW1 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 informationCISC-102 Fall 2018 Week 11
page! 1 of! 26 CISC-102 Fall 2018 Pascal s Triangle ( ) ( ) An easy ( ) ( way ) to calculate ( ) a table of binomial coefficients was recognized centuries ago by mathematicians in India, ) ( ) China, Iran
More informationCS206 Lecture 03. Propositional Logic Proofs. Plan for Lecture 03. Axioms. Normal Forms
CS206 Lecture 03 Propositional Logic Proofs G. Sivakumar Computer Science Department IIT Bombay siva@iitb.ac.in http://www.cse.iitb.ac.in/ siva Page 1 of 12 Fri, Jan 03, 2003 Plan for Lecture 03 Axioms
More informationTopic 1: Propositional logic
Topic 1: Propositional logic Guy McCusker 1 1 University of Bath Logic! This lecture is about the simplest kind of mathematical logic: propositional calculus. We discuss propositions, which are statements
More information1. Consider the conditional E = p q r. Use de Morgan s laws to write simplified versions of the following : The negation of E : 5 points
Introduction to Discrete Mathematics 3450:208 Test 1 1. Consider the conditional E = p q r. Use de Morgan s laws to write simplified versions of the following : The negation of E : The inverse of E : The
More information5. Use a truth table to determine whether the two statements are equivalent. Let t be a tautology and c be a contradiction.
Statements Compounds and Truth Tables. Statements, Negations, Compounds, Conjunctions, Disjunctions, Truth Tables, Logical Equivalence, De Morgan s Law, Tautology, Contradictions, Proofs with Logical Equivalent
More informationChapter 3: Logic. Diana Pell. A statement is a declarative sentence that is either true or false, but not both.
Chapter 3: Logic Diana Pell Section 3.1: Statements and Quantifiers A statement is a declarative sentence that is either true or false, but not both. Exercise 1. Decide which of the following are statements
More informationMath 10850, fall 2017, University of Notre Dame
Math 10850, fall 2017, University of Notre Dame Notes on first exam September 22, 2017 The key facts The first midterm will be on Thursday, September 28, 6.15pm-7.45pm in Hayes-Healy 127. What you need
More informationIt is not the case that ϕ. p = It is not the case that it is snowing = It is not. r = It is not the case that Mary will go to the party =
Introduction to Propositional Logic Propositional Logic (PL) is a logical system that is built around the two values TRUE and FALSE, called the TRUTH VALUES. true = 1; false = 0 1. Syntax of Propositional
More informationn 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 informationDiscrete Mathematics. Instructor: Sourav Chakraborty. Lecture 4: Propositional Logic and Predicate Lo
gic Instructor: Sourav Chakraborty Propositional logic and Predicate Logic Propositional logic and Predicate Logic Every statement (or proposition) is either TRUE or FALSE. Propositional logic and Predicate
More informationSupplementary exercises in propositional logic
Supplementary exercises in propositional logic The purpose of these exercises is to train your ability to manipulate and analyze logical formulas. Familiarize yourself with chapter 7.3-7.5 in the course
More informationThe 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 informationAnnouncements CompSci 102 Discrete Math for Computer Science
Announcements CompSci 102 Discrete Math for Computer Science Read for next time Chap. 1.4-1.6 Recitation 1 is tomorrow Homework will be posted by Friday January 19, 2012 Today more logic Prof. Rodger Most
More informationPropositional 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 informationIntroduction. 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 informationLearning 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 informationFor all For every For each For any There exists at least one There exists There is Some
Section 1.3 Predicates and Quantifiers Assume universe of discourse is all the people who are participating in this course. Also let us assume that we know each person in the course. Consider the following
More information