EP USING+UNDERSTANDING MATH.-MYMATHLAB
6th Edition
ISBN: 9780321922205
Author: Bennett
Publisher: PEARSON CO
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 1.B, Problem 23E
To determine
Explain the meaning of the given statement, which contains a multiple negation. Then answer the question that follows.
Sarah did not decline the offer to go to dinner. Did Sarah go to dinner?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
sy = f(x)
+
+
+
+
+
+
+
+
+
X
3
4
5
7
8
9
The function of shown in the figure is continuous on the closed interval [0, 9] and differentiable on the open
interval (0, 9). Which of the following points satisfies conclusions of both the Intermediate Value Theorem
and the Mean Value Theorem for f on the closed interval [0, 9] ?
(A
A
B
B
C
D
=
Q6 What will be the allowable bearing capacity of sand having p = 37° and ydry
19 kN/m³ for (i) 1.5 m strip foundation (ii) 1.5 m x 1.5 m square footing and
(iii)1.5m x 2m rectangular footing. The footings are placed at a depth of 1.5 m
below ground level. Assume F, = 2.5. Use Terzaghi's equations.
0
Ne
Na
Ny
35 57.8 41.4 42.4
40 95.7 81.3 100.4
Q1 The SPT records versus depth are given in table below. Find qan for the raft 12%
foundation with BxB-10x10m and depth of raft D-2m, the allowable
settlement is 50mm.
Elevation, m 0.5 2
2 6.5 9.5 13 18 25
No.of blows, N 11 15 29 32 30 44
0
estigate shear
12%
Chapter 1 Solutions
EP USING+UNDERSTANDING MATH.-MYMATHLAB
Ch. 1.A - Prob. 1QQCh. 1.A - A fallacy is a. a statement that is untrue. b. a...Ch. 1.A - Which of the following could not qualify as a...Ch. 1.A - An argument in which the conclusion essentially...Ch. 1.A - The fallacy of appeal to ignorance occurs when a....Ch. 1.A - Consider the argument ‘‘I don’t support the...Ch. 1.A - Consider again the argument ‘‘I don’t support the...Ch. 1.A - Prob. 8QQCh. 1.A - Suppose that the fact that an event A occurs...Ch. 1.A - When we speak of a straw man in an argument, we...
Ch. 1.A - What is logic? Briefly explain how logic can be...Ch. 1.A - How do we define an argument? What is the basic...Ch. 1.A - What is a fallacy? Choose three examples of...Ch. 1.A - Prob. 4ECh. 1.A - Prob. 5ECh. 1.A - I persuaded my father that I was right with a...Ch. 1.A - I didn’t believe the premises on which he based...Ch. 1.A - Prob. 8ECh. 1.A - I disagree with your conclusion, so your argument...Ch. 1.A - Even though your argument contains a fallacy, your...Ch. 1.A - Analyzing Fallacies. Consider the following...Ch. 1.A - 11-20: Analyzing Fallacies. Consider the following...Ch. 1.A - Analyzing Fallacies. Consider the following...Ch. 1.A - 11-20: Analyzing Fallacies. Consider the following...Ch. 1.A - Analyzing Fallacies. Consider the following...Ch. 1.A - Prob. 16ECh. 1.A - Analyzing Fallacies. Consider the following...Ch. 1.A - Prob. 18ECh. 1.A - Analyzing Fallacies. Consider the following...Ch. 1.A - Prob. 20ECh. 1.A - Prob. 21ECh. 1.A - Prob. 22ECh. 1.A - Prob. 23ECh. 1.A - Prob. 24ECh. 1.A - Prob. 25ECh. 1.A - Prob. 26ECh. 1.A - Prob. 27ECh. 1.A - Prob. 28ECh. 1.A - Recognizing Fallacies. In the following arguments,...Ch. 1.A - Prob. 30ECh. 1.A - Prob. 31ECh. 1.A - Prob. 32ECh. 1.A - Prob. 33ECh. 1.A - Prob. 34ECh. 1.A - 25-40: Recognizing Fallacies. In the following...Ch. 1.A - Prob. 36ECh. 1.A - Prob. 37ECh. 1.A - Recognizing Fallacies. In the following arguments,...Ch. 1.A - 25-40: Recognizing Fallacies. In the following...Ch. 1.A - Prob. 40ECh. 1.A - Prob. 41ECh. 1.A - Prob. 42ECh. 1.A - Additional Fallacies. Consider the blowing...Ch. 1.A - Additional Fallacies. Consider the blowing...Ch. 1.A - Evaluating Media Information. Choose a current...Ch. 1.A - Snopes. Visit the Snopes.com website and choose...Ch. 1.A - Prob. 47ECh. 1.A - Prob. 48ECh. 1.A - Prob. 49ECh. 1.A - Prob. 50ECh. 1.A - Prob. 51ECh. 1.A - 52. Personal Fallacies. Describe an instance in...Ch. 1.B - The statement Mathematics is fun is a. an...Ch. 1.B - Suppose you know the truth value of a proposition...Ch. 1.B - Which of the following has the form of a...Ch. 1.B - Suppose you want to make a truth table for the...Ch. 1.B - Suppose the statement p or q is true. Then you can...Ch. 1.B - Suppose the statement p is false and the statement...Ch. 1.B - The statement If it’s a dog, then it is a mammal...Ch. 1.B - The statement If the engine is running, then the...Ch. 1.B - Two statements are logically equivalent if a. they...Ch. 1.B - Prob. 10QQCh. 1.B - What is a proposition? Give a few examples, and...Ch. 1.B - What do we mean by the negation of a proposition?...Ch. 1.B - Define conjunction, disjunction, and conditional,...Ch. 1.B - 4. What is the difference between an inclusive or...Ch. 1.B - 5. Make a truth table for each of the following: p...Ch. 1.B - Prob. 6ECh. 1.B - 7. My logical proposition is a question that you...Ch. 1.B - The mayor opposes repealing the ban on handguns,...Ch. 1.B - Prob. 9ECh. 1.B - Prob. 10ECh. 1.B - Prob. 11ECh. 1.B - Prob. 12ECh. 1.B - A proposition? Determine whether the following...Ch. 1.B - A proposition? Determine whether the following...Ch. 1.B - 13-18: A proposition? Determine whether the...Ch. 1.B - A proposition? Determine whether the following...Ch. 1.B - Prob. 17ECh. 1.B - Prob. 18ECh. 1.B - Negation. Write the negation of the given...Ch. 1.B - Negation. Write the negation of the given...Ch. 1.B - Prob. 21ECh. 1.B - Prob. 22ECh. 1.B - Prob. 23ECh. 1.B - Multiple Negations. Explain the meaning of the...Ch. 1.B - Multiple Negations. Explain the meaning of the...Ch. 1.B - Multiple Negations. Explain the meaning of the...Ch. 1.B - Multiple Negations. Explain the meaning of the...Ch. 1.B - Prob. 28ECh. 1.B - Truth Tables. Make a truth table for the given...Ch. 1.B - Prob. 30ECh. 1.B - And Statements. The following propositions have...Ch. 1.B - And Statements. The following propositions have...Ch. 1.B - 31-36: And Statements. The following propositions...Ch. 1.B - Prob. 34ECh. 1.B - Prob. 35ECh. 1.B - Prob. 36ECh. 1.B - Truth Tables. Make a truth table for the given...Ch. 1.B - 37-38: Truth Tables. Make a truth table for the...Ch. 1.B - Prob. 39ECh. 1.B - 39-44: Interpreting or. State whether or is used...Ch. 1.B - Prob. 41ECh. 1.B - Interpreting or. State whether or is used in the...Ch. 1.B - Prob. 43ECh. 1.B - Interpreting or. State whether or is used in the...Ch. 1.B - Truth Table. Make a truth table for the given...Ch. 1.B - Truth Table. Make a truth table for the given...Ch. 1.B - Truth Table. Make a truth table for the given...Ch. 1.B - Truth Table. Make a truth table for the given...Ch. 1.B - Truth Table. Make a truth table for the given...Ch. 1.B - Prob. 50ECh. 1.B - 51-56: Or Statements. The following propositions...Ch. 1.B - Prob. 52ECh. 1.B - Prob. 53ECh. 1.B - Prob. 54ECh. 1.B - Or Statements. The following propositions have the...Ch. 1.B - Prob. 56ECh. 1.B - 57-58: Truth Tables. Make a truth table for the...Ch. 1.B - 57-58: Truth Tables. Make a truth table for the...Ch. 1.B - Prob. 59ECh. 1.B - If…then Statements. Identify the hypothesis and...Ch. 1.B - Prob. 61ECh. 1.B - Prob. 62ECh. 1.B - Prob. 63ECh. 1.B - Prob. 64ECh. 1.B - Prob. 65ECh. 1.B - If…then Statements. Identify the hypothesis and...Ch. 1.B - Prob. 67ECh. 1.B - Prob. 68ECh. 1.B - Prob. 69ECh. 1.B - Rephrasing Conditional Statements. Express the...Ch. 1.B - Prob. 71ECh. 1.B - Prob. 72ECh. 1.B - Prob. 73ECh. 1.B - Converse, Inverse, and Contrapositive. Write the...Ch. 1.B - Converse, Inverse, and Contrapositive. Write the...Ch. 1.B - Prob. 76ECh. 1.B - Prob. 77ECh. 1.B - Converse, Inverse, and Contrapositive. Write the...Ch. 1.B - Prob. 79ECh. 1.B - Prob. 80ECh. 1.B - Prob. 81ECh. 1.B - Prob. 82ECh. 1.B - 83-87: Writing Conditional Propositions. Create...Ch. 1.B - Prob. 84ECh. 1.B - Writing Conditional Propositions. Create your own...Ch. 1.B - 83-87: Writing Conditional Propositions. Create...Ch. 1.B - 83-87: Writing Conditional Propositions. Create...Ch. 1.B - Prob. 88ECh. 1.B - Necessary and Sufficient. Write the following...Ch. 1.B - Prob. 90ECh. 1.B - Prob. 91ECh. 1.B - 89-92: Necessary and Sufficient. Write the...Ch. 1.B - Logical Equivalence. Consider the following pairs...Ch. 1.B - Logical Equivalence. Consider the following pairs...Ch. 1.B - Logical Equivalence. Consider the following pairs...Ch. 1.B - Prob. 96ECh. 1.B - Logical Equivalence. Consider the following pairs...Ch. 1.B - Prob. 98ECh. 1.B - Prob. 99ECh. 1.B - Prob. 100ECh. 1.B - Prob. 101ECh. 1.B - Prob. 102ECh. 1.C - Consider the set {Alabama, Alaska, Arizona,…,...Ch. 1.C - Which of the following is not a member of the set...Ch. 1.C - Based on the Venn diagram below, we conclude that...Ch. 1.C - Suppose that A represents the set of all boys and...Ch. 1.C - Suppose that A represents the set of all apples...Ch. 1.C - Suppose that A represents the set of all high...Ch. 1.C - In the Venn diagram below, the X tells us that a....Ch. 1.C - Prob. 8QQCh. 1.C - Consider again the Venn diagram from Exercise 8....Ch. 1.C - Look at the data in Table 1.1 (p.34). The total...Ch. 1.C - Prob. 1ECh. 1.C - What is a Venn diagram? How do we show that one...Ch. 1.C - List the four standard categorical propositions....Ch. 1.C - Briefly discuss how you can put a categorical...Ch. 1.C - Explain how to draw a Venn diagram for three...Ch. 1.C - 6. Explain how to read a table such as Table 1.1...Ch. 1.C - The payments we make to the electric company are a...Ch. 1.C - All jabbers are wocks, so there must be no wocks...Ch. 1.C - I counted an irrational number of students in my...Ch. 1.C - I surveyed my class to find out whether students...Ch. 1.C - My professor asked me to draw a Venn diagram for a...Ch. 1.C - Prob. 12ECh. 1.C - Prob. 13ECh. 1.C - Prob. 14ECh. 1.C - Prob. 15ECh. 1.C - Prob. 16ECh. 1.C - Prob. 17ECh. 1.C - 13-28: Classifying Numbers. Choose the first set...Ch. 1.C - 13-28: Classifying Numbers. Choose the first set...Ch. 1.C - Prob. 20ECh. 1.C - Prob. 21ECh. 1.C - Prob. 22ECh. 1.C - Prob. 23ECh. 1.C - Prob. 24ECh. 1.C - Prob. 25ECh. 1.C - Prob. 26ECh. 1.C - Prob. 27ECh. 1.C - Classifying Numbers. Choose the first set in the...Ch. 1.C - Prob. 29ECh. 1.C - Prob. 30ECh. 1.C - Prob. 31ECh. 1.C - Prob. 32ECh. 1.C - Prob. 33ECh. 1.C - Prob. 34ECh. 1.C - Prob. 35ECh. 1.C - Prob. 36ECh. 1.C - Prob. 37ECh. 1.C - Prob. 38ECh. 1.C - Venn Diagrams for Two Sets. Draw Venn diagrams...Ch. 1.C - Prob. 40ECh. 1.C - Venn Diagrams for Two Sets. Draw Venn diagrams...Ch. 1.C - Venn Diagrams for Two Sets. Draw Venn diagrams...Ch. 1.C - Prob. 43ECh. 1.C - Prob. 44ECh. 1.C - 45-52: Categorical Propositions. For the given...Ch. 1.C - Categorical Propositions. For the given...Ch. 1.C - Prob. 47ECh. 1.C - Categorical Propositions. For the given...Ch. 1.C - 45-52: Categorical Propositions. For the given...Ch. 1.C - Prob. 50ECh. 1.C - Categorical Propositions. For the given...Ch. 1.C - Prob. 52ECh. 1.C - Prob. 53ECh. 1.C - Prob. 54ECh. 1.C - Prob. 55ECh. 1.C - Prob. 56ECh. 1.C - Prob. 57ECh. 1.C - Prob. 58ECh. 1.C - Prob. 59ECh. 1.C - Two-Circle Venn Diagram with Numbers. Use the Venn...Ch. 1.C - Prob. 61ECh. 1.C - Two-Circle Venn Diagram with Numbers. Use the Venn...Ch. 1.C - Prob. 63ECh. 1.C - Three-Circle Venn Diagram with Numbers. Use the...Ch. 1.C - Three-Circle Venn Diagram with Numbers. Use the...Ch. 1.C - Three-Circle Venn Diagram with Numbers. Use the...Ch. 1.C - Venn Diagram Analysis. 67. Of the 45 theater...Ch. 1.C - Venn Diagram Analysis. 68. All cyclists who...Ch. 1.C - Venn Diagram Analysis. 69. One hundred people who...Ch. 1.C - Prob. 70ECh. 1.C - Prob. 71ECh. 1.C - Prob. 72ECh. 1.C - Prob. 73ECh. 1.C - Prob. 74ECh. 1.C - More Than Three Sets. Draw a Venn diagram that...Ch. 1.C - Prob. 76ECh. 1.C - Prob. 77ECh. 1.C - Prob. 78ECh. 1.C - Prob. 79ECh. 1.C - Prob. 80ECh. 1.C - Prob. 81ECh. 1.C - Prob. 82ECh. 1.C - Prob. 83ECh. 1.C - Prob. 84ECh. 1.C - Prob. 85ECh. 1.C - 86. Categorical Propositions. Find at least three...Ch. 1.C - Prob. 87ECh. 1.C - Prob. 88ECh. 1.C - Prob. 89ECh. 1.C - U.S. Presidents. Collect the following facts about...Ch. 1.D - To prove a statement true, you must use a. an...Ch. 1.D - Prob. 2QQCh. 1.D - Prob. 3QQCh. 1.D - 4. Consider an argument in which Premise 1 is "All...Ch. 1.D - 5. Consider again the argument from question 4....Ch. 1.D - Consider an argument in which Premise 1 is “ If p,...Ch. 1.D - 7. Consider an argument in which Premise 1 is “ If...Ch. 1.D - Prob. 8QQCh. 1.D - 9. The longest side of a right triangle is called...Ch. 1.D - Prob. 10QQCh. 1.D - Summarize the differences between deductive and...Ch. 1.D - Briefly explain the idea of strength and how it...Ch. 1.D - Briefly explain the ideas of validity and...Ch. 1.D - Describe the procedure used to test the validity...Ch. 1.D - Prob. 5ECh. 1.D - What is a chain of conditionals? Give an example...Ch. 1.D - Prob. 7ECh. 1.D - Prob. 8ECh. 1.D - Prob. 9ECh. 1.D - Prob. 10ECh. 1.D - Prob. 11ECh. 1.D - Prob. 12ECh. 1.D - Prob. 13ECh. 1.D - Prob. 14ECh. 1.D - Prob. 15ECh. 1.D - Prob. 16ECh. 1.D - Prob. 17ECh. 1.D - Prob. 18ECh. 1.D - Prob. 19ECh. 1.D - Prob. 20ECh. 1.D - Everyday Logic: Explain whether the following...Ch. 1.D - Prob. 22ECh. 1.D - Prob. 23ECh. 1.D - Prob. 24ECh. 1.D - Analyzing Inductive Arguments. Determine the truth...Ch. 1.D - Prob. 26ECh. 1.D - Prob. 27ECh. 1.D - Prob. 28ECh. 1.D - Prob. 29ECh. 1.D - Analyzing Deductive Arguments. Consider the...Ch. 1.D - Prob. 31ECh. 1.D - Analyzing Deductive Arguments. Consider the...Ch. 1.D - Prob. 33ECh. 1.D - Prob. 34ECh. 1.D - Analyzing Deductive Arguments. Consider the...Ch. 1.D - Prob. 36ECh. 1.D - Prob. 37ECh. 1.D - Prob. 38ECh. 1.D - Prob. 39ECh. 1.D - Prob. 40ECh. 1.D - Prob. 41ECh. 1.D - Deductive Arguments with Conditional Propositions....Ch. 1.D - Prob. 43ECh. 1.D - Prob. 44ECh. 1.D - Prob. 45ECh. 1.D - Prob. 46ECh. 1.D - Prob. 47ECh. 1.D - Prob. 48ECh. 1.D - Prob. 49ECh. 1.D - Prob. 50ECh. 1.D - Testing Mathematical Rules. Test the following...Ch. 1.D - It is true for all positive integers n that...Ch. 1.D - 53-57: Validity and Soundness. State whether it is...Ch. 1.D - 53-57: Validity and Soundness. State whether it is...Ch. 1.D - Prob. 55ECh. 1.D - Prob. 56ECh. 1.D - Validity and Soundness. State whether it is...Ch. 1.D - Prob. 58ECh. 1.D - Prob. 59ECh. 1.D - Prob. 60ECh. 1.D - Prob. 61ECh. 1.D - 62. The Goldbach Conjecture. Recall that a prime...Ch. 1.D - Prob. 63ECh. 1.D - Prob. 64ECh. 1.D - Conditionals in the Literature. Consider the...Ch. 1.D - Prob. 66ECh. 1.D - The Pythagorean Theorem. Learn more about the...Ch. 1.D - Prob. 68ECh. 1.D - 69. Inductive Reasoning in Your Life. Give an...Ch. 1.D - Prob. 70ECh. 1.D - Prob. 71ECh. 1.D - Prob. 72ECh. 1.E - "If you want to save the social services that...Ch. 1.E - 2. Suppose that an argument is deductively valid...Ch. 1.E - 3. You need to buy a car and are considering loans...Ch. 1.E - 4. You get your hair cut at a shop that charges...Ch. 1.E - You buy a cell phone plan that gives you up to...Ch. 1.E - Prob. 6QQCh. 1.E - Prob. 7QQCh. 1.E - Prob. 8QQCh. 1.E - 9. A teacher claims that, because spell checkers...Ch. 1.E - The Smiths have a picnic every Saturday provided t...Ch. 1.E - Describe critical thinking and why it is important...Ch. 1.E - Prob. 2ECh. 1.E - Prob. 3ECh. 1.E - Prob. 4ECh. 1.E - Reed was relieved because his insurance company...Ch. 1.E - 6. Although the plane crashed in Nevada, the...Ch. 1.E - Sue prefers the Red shuttle because it gets her to...Ch. 1.E - Prob. 8ECh. 1.E - There was no price difference, so Michael chose...Ch. 1.E - Prob. 10ECh. 1.E - Prob. 11ECh. 1.E - Prob. 12ECh. 1.E - Prob. 13ECh. 1.E - Prob. 14ECh. 1.E - Prob. 15ECh. 1.E - Prob. 16ECh. 1.E - Prob. 17ECh. 1.E - Prob. 18ECh. 1.E - Prob. 19ECh. 1.E - Prob. 20ECh. 1.E - Prob. 21ECh. 1.E - Prob. 22ECh. 1.E - Interpreting Policies. A city charters sole policy...Ch. 1.E - Reading a Ballot Initiative. Consider the...Ch. 1.E - Hidden Assumptions. Identify at least two hidden...Ch. 1.E - Prob. 26ECh. 1.E - Hidden Assumptions. Identify at least two hidden...Ch. 1.E - Hidden Assumptions. Identify at least two hidden...Ch. 1.E - 29-30: Unstated Issues. The following arguments...Ch. 1.E - Unstated Issues. The following arguments give...Ch. 1.E - IRS Guidelines on Who Must File a Federal Tax...Ch. 1.E - Prob. 32ECh. 1.E - Reading a Lease. Consider the following excerpt...Ch. 1.E - Airline Options. In planning a trip to New Zealand...Ch. 1.E - Buy vs. Lease. You are deciding whether to buy a...Ch. 1.E - You've Won! You receive the following e-mail...Ch. 1.E - Prob. 37ECh. 1.E - Prob. 38ECh. 1.E - Ambiguity in the News. Explain how the direct...Ch. 1.E - Prob. 40ECh. 1.E - Prob. 41ECh. 1.E - Credit Card Agreement. The following rules are...Ch. 1.E - Prob. 43ECh. 1.E - Texas Ethics. In its Guide to Ethics the Texas...Ch. 1.E - Decision Making. Analyze the situations. and...Ch. 1.E - Prob. 46ECh. 1.E - Prob. 47ECh. 1.E - Prob. 48ECh. 1.E - Prob. 49ECh. 1.E - Prob. 50ECh. 1.E - Prob. 51ECh. 1.E - Prob. 52ECh. 1.E - Prob. 53ECh. 1.E - Prob. 54ECh. 1.E - Prob. 55ECh. 1.E - Prob. 56ECh. 1.E - Prob. 57ECh. 1.E - 57-65: Critical Thinking. Consider the following...Ch. 1.E - Prob. 59ECh. 1.E - Prob. 60ECh. 1.E - Prob. 61ECh. 1.E - Prob. 62ECh. 1.E - Prob. 63ECh. 1.E - Prob. 64ECh. 1.E - Prob. 65ECh. 1.E - Prob. 66ECh. 1.E - Interpreting the Second Amendment. Much of the...Ch. 1.E - Prob. 68ECh. 1.E - Prob. 69ECh. 1.E - Prob. 70ECh. 1.E - Prob. 71ECh. 1.E - Prob. 72E
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, subject and related others by exploring similar questions and additional content below.Similar questions
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Discrete Mathematics and Its Applications ( 8th I...MathISBN:9781259676512Author:Kenneth H RosenPublisher:McGraw-Hill EducationMathematics for Elementary Teachers with Activiti...MathISBN:9780134392790Author:Beckmann, SybillaPublisher:PEARSON
- Thinking Mathematically (7th Edition)MathISBN:9780134683713Author:Robert F. BlitzerPublisher:PEARSONDiscrete Mathematics With ApplicationsMathISBN:9781337694193Author:EPP, Susanna S.Publisher:Cengage Learning,Pathways To Math Literacy (looseleaf)MathISBN:9781259985607Author:David Sobecki Professor, Brian A. MercerPublisher:McGraw-Hill Education
Discrete Mathematics and Its Applications ( 8th I...
Math
ISBN:9781259676512
Author:Kenneth H Rosen
Publisher:McGraw-Hill Education
Mathematics for Elementary Teachers with Activiti...
Math
ISBN:9780134392790
Author:Beckmann, Sybilla
Publisher:PEARSON
Thinking Mathematically (7th Edition)
Math
ISBN:9780134683713
Author:Robert F. Blitzer
Publisher:PEARSON
Discrete Mathematics With Applications
Math
ISBN:9781337694193
Author:EPP, Susanna S.
Publisher:Cengage Learning,
Pathways To Math Literacy (looseleaf)
Math
ISBN:9781259985607
Author:David Sobecki Professor, Brian A. Mercer
Publisher:McGraw-Hill Education
Logical Arguments - Modus Ponens & Modus Tollens; Author: Dr. Trefor Bazett;https://www.youtube.com/watch?v=NTSZMdGlo4g;License: Standard YouTube License, CC-BY