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Chapter 27
Shorthand or Pronouns in Logic
Previous Chapters: What is in Chapters 27
to 31.
Note: Online Book Pattern
Based Reason includes this chapter and more on logic
and reason.
1 Pronouns and Shorthand Symbols
The words it, you, I, he and she are pronouns. They can be used
to refer to objects or individuals. Further, from time to time, these pronouns
are used to refer to different objects and different people. The meaning of each
pronoun can last for just a short while, before the given meaning is forgotten
or changed. Pronouns and nicknames provide short ways for talking and writing
about objects and people. Pronouns provide a form of shorthand. Got it?
2 Pronouns and Shorthand Labels
There is only one pronoun it. For each object we meet or have met, we
could say it. But if I say it, which object do I mean? The word it
is easily overused. The single pronoun it is not enough for us. We
need more.
To overcome this difficulty of not having enough pronouns, we may invent our
own names, labels or pronouns for people and objects. Then in speaking about a
person or object, we use a name, label or individual pronoun. Here letters and
other symbols (the choice is wide) can serve as short names, labels or extra
pronouns. We can have one name or pronoun for each person or object we talk
about.
In logic, we can talk about events like (i) Aunt Jane visits, (ii) the cat
climbs a tree, or (iii) Tom plays. In speaking about one of these events we
could use the pronoun it, or we could mention the name of the event, or
we could provide a temporary (?) shorthand label. For example, we can talk about
event A, or event B. The shorthand letters here serve as names or extra
pronouns. So we can say event A, or event B, or event M. For more labels, we can
number the people or objects. This further helps to identify them. For instance,
we can refer to the first situation A, the second situation B, the third
situation C .... Doing both, that is assigning numbers and labels is acceptable,
although this introduces redundancy.
3 Shorthand Notation
One way implication rules can be written in many forms. For instance, the
four phrases in the left column of the following table all have the same
meaning. To avoid writing these phrases in their longhand form, we can use
compact, or more compact shorthand notation (symbols), etc.
| Phrase |
Shorthand Notation |
| if A then B |
A Þ B |
| A implies B |
A Þ B |
| B if A |
B Ü A |
| B is implied by A |
B Ü A |
Compact forms for the shorthand phrase A if and only if B are given by
A iff B and by AÛ B. In place
of A if and only if B, we may say situation A is equivalent to situation
B or, more briefly, A is equivalent to B. The four phrases in the left
column of the next table all have the same meaning and the same shorthand form.
| Phrase |
Shorthand Notation |
| A is equivalent to B |
A Û B |
| A if and only if B |
A Û B |
| A iff B |
A Û B |
| A when and only when B |
A Û B |
The four phrases and the shorthand notation A Û
B are interchangeable. We can use one in place of any other as we like or
just for the sake of variety while talking or writing.
Next Chapter: Chapter 28 Occurrence Tables - a
way to provide context for truth tables (or an alternative).
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Three Skills
For
Algebra
Volume 2
Printed in Canada
ISBN 0-9697564-2-9
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Read slowly, this work may enrich your
skills & knowledge. Take the risk.
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Chapters and Appendices
Foreword 1. Introduction 2. Implication Rules [4] 3. Chains of Reason [3] 4. Induction Mathematical 4. Romeo and Juliet 6 Old Language 5 Knowledge Islands [2] 7 Arith Skill Check [4 X 2] Arith Webvideos 7. The Next Chapters 8 The Three Skills 8 VNR-Concise-Encyclopedia PS. What is a Variable [8] 9. Algebra Talk [7] 10 Two More Skills[5] 11 Why Shorthand 12 Shorthand Usage [10] 13 What's Next PS: The 4-th Skill For Algebra 14 Compound Interest [6] 15 Linear Equations [5] 16 Painless Proofs 17 Pythagoras PS I. Distributive Law PS II. Polynomials 18 Rules of Algebra [20] 19 Functions & Sets 20 Degrees & Radians 21 What's Next 22. Arith & Geometric Sums [2] 23 Summation Notation 24 Your Money [3] 25 Induction & Recursion [4] 26 What's Next 27 Pronouns in Logic 28 Occurrence Tables 29 Contrapositive 30 Truth Tables 31 Indirect Reason Pathways for Learning
Book Entrance
What is a Variable?
Introduction
Variation between Examples
Variation of Letters
A letter denotes a variable
Cases of Double Variation
Three Notions of a Variable
Constants, Parameters
& Variables
Talking about numbers
Dependent
or Independent
Variable, a Matter of Choice
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For
Senior
High School & Calculus Students
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<| (o) (o)
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/
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-/[]\-
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Words to clearly
introduce algebra and variables
have been missing in course design. For people who cannot do
algebra,
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the missing words may
explain or ease their difficulties. Volume 2 ,Three
Skills for Algebra, in Chapters
8 to 14 & 18 etc, puts words before symbols to
providing the missing words in a way that enrich the
comprehension of all. Those words form the middle part of a algebra
(and logic) lessons aimed at helping or improving all
of high school mathematics and also calculus course
design & delivery.
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For Avid Readers in School & Out -
Online Books
1. Elements of
Reason. 1996
1A. Pattern
Based Reason 1995
1B. Math
Curriculum Notes 1996
2. Three
Skills for Algebra 1995
3.Why
Slopes & More.Math
1995
Tour their forewords.
Calculus Prep or Help: See Volumes 2 & 3,
and this bigger
Calculus
Guide. If your
calculus questions is not answered here, submit
it. Over time, that may complete the site development of
calculus.
For Parents: Speaking
Skills, Reading
& Writing,
Preparing for Science, ends,
values and methods for work and study, parent- friendly maths
skill development booklets for ages 4-14.
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Mostly
For High
School
Intro to Solving
Linear Equations
- a different paths for junior and even senior high
school students. Question for Tutors: When do
you use and when you skip the stick diagram method
here?
Fraction
Skills, thought-based development, Ages 10 to 14 may need a
tutor. Students who have to understand in order
to do may like the development in all or part.
For Senior
High School Mathematics & Calculus
5
wordy Logic
Chapters
4 curious Algebra
Chapters
Words before & besides symbols. A Key Algebra
forward & backwards Chapter
First Calculus
Preview (1st intro)
Four Calculus
Chapters
(2nd intro)
Intro to Complex
Numbers (long)
Intro to Mathematical
Induction (romantic & wordy at first)
Tutors & Instructors:
These lessons introduce skills differently Would you
recommend them?
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More Topics
1. Decimal
Arithmetic Reference!
2. Integers
- Intro to Signed No.s
3. Fractions
- fully explained.
4. Fractions
with Units
5. Number
Theory,
6. Solving
Linear Equations
7 Formulas
for- & backwards -
8. Proportionality,
Back- & For-wards.
9. Logic
Chapters:
10. Euclidean-Geometry
11. Slopes
& Equations of Straight Lines. (Take
I. See take II below)
12. Why
Study Slopes.
13. Maps,
Plans, Similarity & Trig,
(Take II included here)
14. Quadratics:
Starter lessons
15. Polynomials:
Starter lessons
16 Why
Factor Polynomials:
17 Functions
- Forwards & Backwards.
18. Exponents,
Radicals & logs.
19. Complex
Numbers before trig (new advance/ starter lesson)
20. DC
Electric
Circuits Etc
21. Real
Analysis
22. The
Olde Complex No, Trig
& Vector Section.
23. More
Calculus Stuff
- written after Volumes 2 and 3.
Level I Material: New Stuff
Time and Date Matters
Level I Arithmetic.
Money Matters
Measurement Matters
Matters of Chance (Risk Control)
Logic
Chapters
(leave what's not clear in Level I to Level II)
Using/Making Maps and Plans.
(A variant of
Maps,
Plans, Similarity & Trig, to
appear here).
For Instructors
-
Education
Essays
(opinions,
possibilities, references)
- Free
Advice and Directions for teaching primary & high school maths
will be given in online meeting place with voice &
whiteboard.
- Math & Logic How-TOs
1. Arithmetic
2. Algebra
3. More Algebra
4. Beginner Geometry
5. More Geometry
6. Calculus
7. Show Work or Logic
These may be too dense for students. Offering ideas to change
education makes this site different. Nothing
ventured, nothing gained. Site material is
mathematically correct, and where not, please report
errors. The two level program POMME in the site
entrance implies multiple paths for instruction. Supporting
those paths in turn implies a clear destination for
site development and perhaps a new name.
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