Transcript Slide 1

Intro to Logic Theory
Statement -
Intro to Logic Theory
Statement – A sentence that is either true or
false, but not both simultaneously
Intro to Logic Theory
Statement – A sentence that is either true or
false, but not both simultaneously
Truth Value –
Intro to Logic Theory
Statement – A sentence that is either true or
false, but not both simultaneously
Truth Value – The truth or falsity of a
statement
Intro to Logic Theory
Statement – A sentence that is either true or
false, but not both simultaneously
Examples of Statements
E-mail is a way to communicate
Intro to Logic Theory
Statement – A sentence that is either true or
false, but not both simultaneously
Examples of Statements
E-mail is a way to communicate
Newton is the capitol of New Jersey
Intro to Logic Theory
Statement – A sentence that is either true or
false, but not both simultaneously
Examples of Statements
E-mail is a way to communicate
Newton is the capitol of New Jersey
6+5>4
Intro to Logic Theory
Statement – A sentence that is either true or
false, but not both simultaneously
Examples of Statements
E-mail is a way to communicate
Newton is the capitol of New Jersey
6+5>4
11+6=12
Intro to Logic Theory
The following examples are NOT statements
Intro to Logic Theory
The following examples are NOT statements
Access the file
Intro to Logic Theory
The following examples are NOT statements
Access the file
Is this a great country or what?
Intro to Logic Theory
The following examples are NOT statements
Access the file
Is this a great country or what?
A-Rod is better than Derek Jeter
Intro to Logic Theory
The following examples are NOT statements
Access the file
Is this a great country or what?
A-Rod is better than Derek Jeter
This sentence is false
Intro to Logic Theory
The following examples are NOT statements
Access the file
Is this a great country or what?
A-Rod is better than Derek Jeter
This sentence is false
4+5+6
Intro to Logic Theory
Compound Statement -
Intro to Logic Theory
Compound Statement - A sentence that is
comprised of two or more statements. The
statements are connected by such words as
“or” “and” “not” “if…then”
Intro to Logic Theory
Examples of Compound Statements
Intro to Logic Theory
Examples of Compound Statements
Shakespeare wrote sonnets and the poem has 5 verses
Intro to Logic Theory
Examples of Compound Statements
Shakespeare wrote sonnets and the poem has 5 verses
You can pay me now or you can pay me later
Intro to Logic Theory
Examples of Compound Statements
Shakespeare wrote sonnets and the poem has 5 verses
You can pay me now or you can pay me later
If he said it, then it must be true
Intro to Logic Theory
Examples of Compound Statements
Shakespeare wrote sonnets and the poem has 5 verses
You can pay me now or you can pay me later
If he said it, then it must be true
The statement – “My pistol was made by Smith and
Wesson” is NOT a compound statement because in this
case, the word and is not used as a statement connector
Intro to Logic Theory
Negation – A statement that is formed by
making an alteration to a given statement,
which makes a true statement false, or a false
statement true.
Intro to Logic Theory
Write the negation of each statement
Intro to Logic Theory
Write the negation of each statement
I do not like green eggs and ham
Intro to Logic Theory
Write the negation of each statement
I do not like green eggs and ham
I do like green eggs and ham
Intro to Logic Theory
Write the negation of each statement
It is going to snow
Intro to Logic Theory
Write the negation of each statement
It is going to snow
It is not going to snow
Intro to Logic Theory
Write the negation of each statement
Pluto is not a planet
Intro to Logic Theory
Write the negation of each statement
Pluto is not a planet
Pluto is a planet
Intro to Logic Theory
Write the negation of each statement
Gil Hodges will be in the Hall of Fame
Intro to Logic Theory
Write the negation of each statement
Gil Hodges will be in the Hall of Fame
Gill Hodges will not be in the Hall of Fame
Intro to Logic Theory
Write the negation of each statement
x  4  y 5
Intro to Logic Theory
Write the negation of each statement
x  4  y 5
x  4  y 5
Intro to Logic Theory
Quantifiers – Words that make a generalized
statement
Intro to Logic Theory
Quantifiers – Words that make a generalized
statement
Some common quantifiers are all, some none
Intro to Logic Theory
Examples of quantified statements
All dogs are bad
Some guys have all the luck
None of these batteries are worth the money
Intro to Logic Theory
Writing the negation of a quantified statement
requires some thought
Intro to Logic Theory
Writing the negation of a quantified statement
requires some thought
All dogs are bad
Intro to Logic Theory
Writing the negation of a quantified statement
requires some thought
All dogs are bad
Not all dogs are bad
Intro to Logic Theory
Writing the negation of a quantified statement
requires some thought
All dogs are bad
Not all dogs are bad
Some dogs are not bad
Intro to Logic Theory
Writing the negation of a quantified statement
requires some thought
All dogs are bad
Not all dogs are bad
Some dogs are not bad
Notice that if the initial statement is true, then
the negation must be false, and vice versa
Intro to Logic Theory
Writing the negation of a quantified statement
requires some thought
All dogs are bad
Is the statement Some dogs are bad a
negation?
Intro to Logic Theory
Writing the negation of a quantified statement
requires some thought
All dogs are bad
Is the statement Some dogs are bad a
negation?
No, because BOTH statements can be either
true or false simultaneously.
Intro to Logic Theory
A statement and its negation MUST ALWAYS
have opposite truth values
Intro to Logic Theory
Write the negation of each statement
Some guys have all the fame
Intro to Logic Theory
Write the negation of each statement
Some guys have all the fame
No guys have all the fame
Intro to Logic Theory
Write the negation of each statement
Every dog has its day
Intro to Logic Theory
Write the negation of each statement
Every dog has its day
Not every dog has its day
Intro to Logic Theory
Write the negation of each statement
All dogs have their day
Intro to Logic Theory
Write the negation of each statement
All dogs have their day
Not all dogs have their day
At least one dog does not have its day
Intro to Logic Theory
Write the negation of each statement
All dogs have their day
No dogs have their day is NOT a proper
negation because if one dog has its day and
another dog doesn’t have its day, then BOTH
the statement and its negation would be FALSE
Intro to Logic Theory
Write the negation of each statement
Some dogs have their day
Intro to Logic Theory
Write the negation of each statement
Some dogs have their day
No dogs have their day
Intro to Logic Theory
Write the negation of each statement
No dogs had their day
Intro to Logic Theory
Write the negation of each statement
No dogs had their day
Some dogs had their day
At least one dog had its day
Intro to Logic Theory
Write the negation of each statement
No dogs had their day
Can we say “All dogs had their day” is a
negation of the statement above?
Homework, pg 99-100 #1-32
Decide whether each of the following is a
statement or is not a statement,
1. December 7, 1941, was a Sunday.
2. The ZIP code for Manistee, MI, is 49660.
3. Listen, my children, and you shall hear of the
mid-night ride of Paul Revere.
4. Yield to oncoming traffic.
5. 5 + 8 = 13 and 4 - 3 =1
Homework, pg 99-100 #1-32
Decide whether each of the following is a
statement or is not a statement,
1. December 7, 1941, was a Sunday. Yes
2. The ZIP code for Manistee, MI, is 49660. Yes
3. Listen, my children, and you shall hear of the
mid-night ride of Paul Revere. No
4. Yield to oncoming traffic. No
5. 5 + 8 = 13 and 4 - 3 =1 Yes
Homework, pg 99-100 #1-32
Decide whether each of the following is a
statement or is not a statement,
6. 5 + 8 = 12 or 4 — 3 = 2
7. Some numbers are negative.
8. Andrew Johnson was president of the United
States in 1867.
9. Accidents are the main cause of deaths of
children under the age of 8.
10. Star Wars: Episode I—The Phantom Menace
was the top-grossing movie of 1999.
Homework, pg 99-100 #1-32
Decide whether each of the following is a
statement or is not a statement,
6. 5 + 8 = 12 or 4 — 3 = 2 Yes
7. Some numbers are negative. Yes
8. Andrew Johnson was president of the United
States in 1867. Yes
9. Accidents are the main cause of deaths of
children under the age of 8. Yes
10. Star Wars: Episode I—The Phantom Menace
was the top-grossing movie of 1999. Yes
Homework, pg 99-100 #1-32
Decide whether each of the following is a
statement or is not a statement,
11. Where are you going today?
12. Behave yourself and sit down.
13. Kevin “Catfish” McCarthy once took a
prolonged continuous shower for 340 hours, 40
minutes.
14. One gallon of milk weighs more than 4
pounds.
Homework, pg 99-100 #1-32
Decide whether each of the following is a
statement or is not a statement,
11. Where are you going today? No
12. Behave yourself and sit down. No
13. Kevin “Catfish” McCarthy once took a
prolonged continuous shower for 340 hours, 40
minutes. Yes
14. One gallon of milk weighs more than 4
pounds. Yes
Homework, pg 99-100 #1-32
Decide whether each of the following
statements is compound.
15. 1 read the Chicago Tribune and I read the
New York Times.
16. My brother got married in London.
17. Tomorrow is Sunday.
18. Dara Lanier is younger than 29 years of age,
and so is Teri Orr.
Homework, pg 99-100 #1-32
Decide whether each of the following
statements is compound.
15. 1 read the Chicago Tribune and I read the
New York Times. Yes
16. My brother got married in London. No
17. Tomorrow is Sunday. No
18. Dara Lanier is younger than 29 years of age,
and so is Teri Orr. Yes
Homework, pg 99-100 #1-32
Decide whether each of the following
statements is compound.
19. Jay Beckenstein’s wife loves Ben and Jerry’s ice
cream.
20. The sign on the back of the car read “California
or bust!”
21. If Julie Ward sells her quota, then Bill Leonard
will be happy.
22. If Mike is a politician, then Jerry is a crook.
Homework, pg 99-100 #1-32
Decide whether each of the following
statements is compound.
19. Jay Beckenstein’s wife loves Ben and Jerry’s ice
cream. No
20. The sign on the back of the car read “California
or bust!” No
21. If Julie Ward sells her quota, then Bill Leonard
will be happy. Yes
22. If Mike is a politician, then Jerry is a crook. Yes
Homework, pg 99-100 #1-32
Write a negation for each of the following
statements.
23. Her aunt’s name is Lucia.
Homework, pg 99-100 #1-32
Write a negation for each of the following
statements.
23. Her aunt’s name is Lucia.
Her aunt’s name is not Lucia
Homework, pg 99-100 #1-32
Write a negation for each of the following
statements.
24. The flowers are to be watered.
Homework, pg 99-100 #1-32
Write a negation for each of the following
statements.
24. The flowers are to be watered.
The flowers are not to be watered
Homework, pg 99-100 #1-32
Write a negation for each of the following
statements.
25. Every dog has its day.
Homework, pg 99-100 #1-32
Write a negation for each of the following
statements.
25. Every dog has its day.
Not every dog has its day
Homework, pg 99-100 #1-32
Write a negation for each of the following
statements.
26. No rain fell in southern California today.
Homework, pg 99-100 #1-32
Write a negation for each of the following
statements.
26. No rain fell in southern California today.
Some rain fell in southern California today.
Homework, pg 99-100 #1-32
Write a negation for each of the following
statements.
27. Some books are longer than this book.
Homework, pg 99-100 #1-32
Write a negation for each of the following
statements.
27. Some books are longer than this book.
No books are longer than this book.
Homework, pg 99-100 #1-32
Write a negation for each of the following
statements.
28. All students present will get another chance.
Homework, pg 99-100 #1-32
Write a negation for each of the following
statements.
28. All students present will get another chance.
Not all students present will get another chance.
Some students present will not get another chance
At least one student present will not get another
chance
Homework, pg 99-100 #1-32
Write a negation for each of the following
statements.
29. No computer repairman can play blackjack.
Homework, pg 99-100 #1-32
Write a negation for each of the following
statements.
29. No computer repairman can play blackjack.
Some computer repairmen can play blackjack
At least one computer repairman can play blackjack.
Homework, pg 99-100 #1-32
Write a negation for each of the following
statements.
30. Some people have all the luck.
Homework, pg 99-100 #1-32
Write a negation for each of the following
statements.
30. Some people have all the luck.
No people have all the luck.
Homework, pg 99-100 #1-32
Write a negation for each of the following
statements.
31. Everybody loves somebody sometime.
Homework, pg 99-100 #1-32
Write a negation for each of the following
statements.
31. Everybody loves somebody sometime.
Not everybody loves somebody
At least one person does not love somebody
Homework, pg 99-100 #1-32
Write a negation for each of the following
statements.
32. Everyone loves a winner.
Homework, pg 99-100 #1-32
Write a negation for each of the following
statements.
32. Everyone loves a winner.
Not everyone loves a winner.
Some people do not love a winner.
At least one person does not love a winner.
If you are having some difficulty, see me
for extra help, or…..
If you are having some difficulty, see me
for extra help, or…..
You can get assistance from someone
who is VERY smart……
Symbols in Logic Theory
Let p represent the statement “The costumes are scary” and
Let q represent the statement “The weather is warm”
Write a statement to represent the following
~p
Symbols in Logic Theory
Let p represent the statement “The costumes are scary” and
Let q represent the statement “The weather is warm”
Write a statement to represent the following
~p
The costumes are not scary
Symbols in Logic Theory
Let p represent the statement “The costumes are scary” and
Let q represent the statement “The weather is warm”
Write a statement to represent the following
~q
Symbols in Logic Theory
Let p represent the statement “The costumes are scary” and
Let q represent the statement “The weather is warm”
Write a statement to represent the following
~q
The weather is not warm
Symbols in Logic Theory
Let p represent the statement “The costumes are scary” and
Let q represent the statement “The weather is warm”
Write a statement to represent the following
pq
Symbols in Logic Theory
Let p represent the statement “The costumes are scary” and
Let q represent the statement “The weather is warm”
Write a statement to represent the following
pq
The costumes are scary and the
weather is warm
Symbols in Logic Theory
Let p represent the statement “The costumes are scary” and
Let q represent the statement “The weather is warm”
Write a statement to represent the following
pq
Symbols in Logic Theory
Let p represent the statement “The costumes are scary” and
Let q represent the statement “The weather is warm”
Write a statement to represent the following
pq
The costumes are scary or the
weather is warm
Symbols in Logic Theory
Let p represent the statement “The costumes are scary” and
Let q represent the statement “The weather is warm”
Write a statement to represent the following
~ pq
Symbols in Logic Theory
Let p represent the statement “The costumes are scary” and
Let q represent the statement “The weather is warm”
Write a statement to represent the following
~ pq
The costumes are not scary or the
weather is warm
Symbols in Logic Theory
Let p represent the statement “The costumes are scary” and
Let q represent the statement “The weather is warm”
Write a statement to represent the following
p ~ q
Symbols in Logic Theory
Let p represent the statement “The costumes are scary” and
Let q represent the statement “The weather is warm”
Write a statement to represent the following
p ~ q
The costumes are scary and the
weather is not warm
Conjunction
AND

3 2  5
3 26
3  2  5 and 3 2  6
T
T
T
3 2  5
3 25
3  2  5 and 3 2  5
T
3 2  6
F
3 26
F
3  2  6 and 3 2  6
F
T
F
3 2  6
F
3 25
F
3  2  6 and 3 2  5
F
Disjunction
OR

3 2  5
T
3 26
T
3  2  5 or 3 2  6
T
3 2  5
3 25
3  2  5 or 3 2  5
T
3 2  6
F
3 26
T
3  2  6 or 3 2  6
F
T
T
3 2  6
F
3 25
F
3  2  6 or 3 2  5
F