Parents: Help your child or teen

Online Volumes (Book Orders)
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

More Site Areas 
1.  Solving Linear Equations  2005
2.-Fractions-Rates-Proportns-Units-2006
3.  Algebra, Odds & Ends, HS level-2001
4.-Euclidean-Geometry/Complex No.s 
5.  Analytic Geometry/Functions 2006
6.  Number Theory. 2006-7
7.  Complex Numbers More 2001
8.  Calculus Introduction 2005
More Site Areas 
9   Real  Analysis 1995
10. Secondary IV? maths 2006-7
11. Math Education Essays  2006-7
12. LaTeX2HotEqn: 2004
13. Electric Circuits Etc  2007
14. Quebec Math Education 2004
15-Prequel-to-the-How-TOs-06-2008
How TOs/ Ref.-08- 2008
1. Arithmetic Reference
2. Algebra 
3. More Algebra 
4. Geometry  
5. More Geometry
6. Calculus
7. Logics in Maths


Employ an online or offline tutor at your own risk from 

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USA:  wiziq.com
USA: ziizoo.com

YOU are better than YOU think. Show yourself  how:

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 For better work & study skills, read logic chapters 1 to 5  in  Three Skills for Algebra. Sooner is better. Good luck.

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 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

Do not leave here without it -  Logic mastery  will develops critical thinking, improve reading and writing, and give a firmer base for work and studies at many levels. Good luck.

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Caution: Site advice is approximately correct, for some circumstances, not all. Site How-TOs are logically developed, but not tried and tested. That leaves room for thought and refinement..

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After logic  (a) continue reading Three Skills for Algebra, chapters 8 to 14  and do so alongside site area on solving linear2007 Equations ; or (b) see this calculus starter lesson and Volume 3, Why Slopes  & More Math, chapters 2 to 6;


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.


Explore collaborative whiteboards from groupboardtwiddla  or scriblink.


Occurrence Table for Two Way Implications, Chapter 21, part III

Previous: Chapter 21, Part II, Occurrence Table for Material Implications

3  Two-Way Implication Rules

A rule which can be stated, or restated, in the form
  The first situation A occurs when and only when the second situation B occurs
or in the form
The first situation A occurs if and only if the second situation B occurs
  is called a two-way implication rule. For each two-way implication rule note that:

  1. The rule is obeyed when both situations occur.

  2. The rule is disobeyed when the first situation A occurs without the second situation B occurring.

  3. The rule is disobeyed when the second situation B occurs without the first situation A.

  4.  

  5. The rule is not disobeyed when both situations do not occur.

In brief, the two situations in a two-way implication rule must both occur or both must not occur, for the rule to be not disobeyed.

The next table summarizes the above remarks for any two-way implication rule A if and only if B.

row situation A situation B A if and only if B
1 occurs occurs obeyed
2 occurs occurs not disobeyed
3 occurs not occurs disobeyed
4 occurs not occurs not not disobeyed


As said before, a two-way implication rule is said to be always true when it is never disobeyed. This requires that the situations in rows 2 and 3 of the above table do not occur. That is, the above two-way implication rule A iff B is true (never disobeyed) provided neither of the situations A and B occurs without the other.

 


Links to Chapter Sections: [Special Use of Three Words] 21. Material Implication Occurrence Table ] [ Occurence Table for IFF ] 21. Converses for 1-Way Implications ]

Next: Chapter 21, Part IV, Converses for One Implications

www.whyslopes.com
Volume 1A, Pattern Based Reason

 Chapters 1 to 24

FOREWORD
Three Remarks

1 Introduction
2 Communication
3. Elements of Reason
4 Implication Rules
5. Deception
6 Chains of Reason
7 Longer Chains
For & From Consistency
8. Language Change
9 Next Chapters
10 Responsibility
11 Accidental Patterns
12 Knowledge Islands
13 Euclidean Logic
14 Deductive & Empirical 
     Views of Mathematics

15 Objectivity
16 Origin of Rules
and Patterns
17 Objective Ways

18. Waking up
19. Symbols  & Logic
20. Pronouns or Symbols
21. Truth Tables I.
22. Truth Tables II
22. Biconditional
22. Contrapositive
23. IF-THEN table
24. Indirect Reason Again

To reason often means to persuade someone of the need for an idea or action. That someone could be yourself. So be careful.

1A Logic Postscripts
- online only

+Proof by Absurdity alias proof by contradiction
+How the demand for consistency supports the law of the excluded middle
+Reality versus or with the aid of Imagination
+Links for reason, logic and crtical thinking
+Three Remarks
+History Lost or Missing

There is a difference between
knowing how to spend money,
and having money to spend.

There is likewise a difference
between mastering a skill
and having meeting a situation in which it applies.

 



 


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