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Appetizers and Lessons for Mathematics and Reason 
a calculus and preparation for calculus website, etc.

Online Volumes (Book Orders)
1,  Elements of Reason.
1A. Pattern Based Reason 
1B. Math Curriculum Notes
2. Three Skills for Algebra
3. Why Slopes & More Math

Mathematics Course Designers: LAMP offers food for thought.
More Site Areas 
1. Help Your Child or Teen Learn 
2. Solving Linear Equations
3. Fractions Ratios Rates Proportions & Units
4. Euclidean Geometry
5. Analytic Geometry/Functions 
6. Number Theory
7. More Calculus
More Site Areas 
8. Complex Numbers 
9. Qc Maths  Education  
10. Secondary IV(?) maths
11. Real  Analysis 
12. LaTeX2HotEqn:
13. Electric Circuits Etc  
14.  Français
15. Algebra, Odds & Ends, Etc
More Site Areas 
16. Math Education Essays
17. Telling & Working with Time
18. Maps, Plans & Drawings
19. Quantitative Skills for  home, shopping and work 
20. Statistics Useful, or Not.
Try the
Twiddla Whiteboard
to work online with others.

||Définition d'une variable || Algèbre || Arithmetique || Logique ||La raison basée sur les règles et modelés||
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YOU are better than YOU think. Show yourself  how:  

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Read  logic chapters 1 to 5  in online volume Three Skills for Algebra  for greater skills & confidence in  work 
and study.

Learn to read notes and textbooks like a lawyer, so that no nuance, no subtlety and no clause escapes your attention.

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 Logic chapters 1 to 5  re- appear not in sequence, as is or longer,  in  Volume 1A,  Pattern Based Reason, Bon Appetite.

Logic Mastery
 Amazing, Amusing, Amorous,  Delicious, Delightful, Edifying, Strengthening Elixir. 
It eases work & learning difficulties Makes the hard easier. Opens eyes. Leads to greater precision.
in reading and
writing

Logic mastery makes the hard, easier. Logic mastery  leads to better, stronger and richer comprehension.  Logic mastery  improves reading and writing.  Logic mastery ease learning difficulties.  Logic mastery gives a headstart.  In sum, logic mastery  will develops critical thinking, improve reading and writing, and give a firmer base for work and studies at many levels. Good luck.


After logic  (a) continue reading Three Skills for Algebra, chapters 8 to 14  and do so alongside site area on solving liinear Equations ; or (b) see this calculus starter lesson and Volume 3, Why Slopes  & More Math, chapters 2 to 6;

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Caution: Site advice is approximately correct, for some circumstances, not all. That leaves room for thought

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What may be learnt and when depends on how skills and concepts are developed. Making the hard easier and clearer will allow earlier & richer development of skills and concepts.


Try the Twiddla Whiteboard. In principle, it  allows to people to draw and chat together online on a copy of this webpage or a clean sheet. The chat may be via text or audio.  Visit www.twiddla.com to set up whiteboards to work with the webpage of your choice.

For online automated help in senior high school maths & calculus, visit  quickmath.com  For Automatic Calculus and Algebra Help with derivatives, integrals, graphs, linear equations, matrix algebra, visit calc101.com  With  overlap, each site quickmath & calc101offers a different range of services, some free, some not, all based on webmathematica. Good luck.

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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2. Three Skills for Algebra 

Foreword, Chapters 
& Appendices 

Foreword
1. Introduction
2. Implication Rules
3. Chains of Reason
4. Romeo and Juliet
4. Induction Mathematical
5 Knowledge Islands
6  Old Language
7  Arith Skill Check
7. The Next Chapters
8 The Three Skills
8 VNR-Concise-Encyclopedia
PS. What is a Variable
9. Algebra Talk
10 Two More Skills
11 Why Shorthand
12 Shorthand Usage
13 What's Next
14 Compound Interest
15 Linear Equations
PS I.  Distributive Law
PS II. Polynomials
16 Painless Proofs
17 Pythagoras
18 Rules of Algebra
19  Functions & Sets
20 Degrees & Radians
21 What's Next
22. Arith & Geometric Sums
23 Summation Notation
24 Your Money
25 Induction & Recursion
26 What's Next
27 Pronouns in Logic
28 Occurrence Tables
29 Contrapositive
30 Truth Tables
31 Indirect Reason
A. Advice For Learning

Real Player Videos

Perfect arithmetic skills with whole numbers & fractions
after or besides chapters 1 to 14.

Arithmetic Videos Summary
Addition with Decimals
Subtraction with Decimals
Multiplication with Decimals
Fraction Arithmetic
Recognizing Primes
Long Division for Decimals
Square Root Simplification
Greatest Common Divisors
Least Common Multiples

Words Before Symbols: 
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

Complex number: starter lesson  

Solving Linear Equations:

A. Letters and Lengths

B. & C. Solving Linear Eq'ns
with stick diagrams.

(i) x + 20 = 29
(ii) 2x + 5 = 20
(iii) 3x + 10 = 32
(iv) 5a + 16 = 3a+ 24

(v)  (½)x + 8 = 24½
(vI)  (¾)a + 16 = (¼)a+ 24
(vii) (¾)q + 17 = 32
(viii) 13 =[2/3]x +7 twice
(x) Animated Examples
(i) Integral Coefficients (A)
(ii) Integral Coefficients (B)
(iii) Fractional Coefficients

(iv) With Parameters

Problem Solving with Linear
Equations in one or many
unknowns, and in essentially 
one unknown - Symbols before
words. 


C. Solving Linear Eq'ns 
without
Stick Diagrams

D. Problems in 
essentially one unknown

E: 2D Systems - Sub Methods.
F. Larger Systems



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a 1983 McGill. Ph. D. in mathematics
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