Showing posts with label real variables. Show all posts
Showing posts with label real variables. Show all posts

Friday, September 14, 2012

12. Propositions connecting real and apparent variables

Harold R. (Hal) Foster’s Prince Valiant
© Respective copyright/trademark holders.
Propositions connecting real and apparent variables

 The most important propositions connecting real and apparent variables are the following:

(1) " When a propositional function can be asserted, so can the proposition that all values of the function are true." Stated more briefly, if less exactly, "what holds of any, however chosen, holds of all." This translates itself into the rule that when a real variable occurs in an assertion, we may turn it into an apparent variable by putting the letter representing it in brackets immediately after the assertion-sign.

(2) " What holds of all, holds of any," i.e.

: (x). φx . É . φy.

This states " if φx is always true, then φy is true."

(3) " If φy is true, then φx is sometimes true," i.e.

: φy . É . ($x). φx.

An asserted proposition of the form "($x) . φx" expresses an "existence theorem," namely " there exists an x for which φx is true." The above proposition gives what is in practice the only way of proving existence-theorems: we always have to find some particular y for which φy holds, and thence to infer "($x). φx." If we were to assume what is called the multiplicative axiom, or the equivalent axiom enunciated by Zermelo, that would, in an important class of cases, give an existence-theorem where no particular instance of its truth can be found.

In virtue of " : (x). φx . É. φy" and ": φy . É . ( x). φx," we have

": (x) . φx . É . ($x). φx," i.e. "what is always true is sometimes true. "This would not be the case if nothing existed; thus our assumptions contain the assumption that there is something. This is involved in the principle that what holds of all, holds of any; for this would not be true if there were no " any."

(4)"If φx is always true, and yx is always true, then 'φx . yx' is always true,"' i.e.

:. (x). φx : (x). yx: É (x) . φx . yx.

(This requires that φ and y should be functions which take arguments of the same type. We shall explain this requirement at a later stage.) The converse also holds; i.e. we have

:. (x). φx . yx . É : (x). φx : (x). yx.

It is to some extent optional which of the propositions connecting real and apparent variables are taken as primitive propositions. The primitive propositions assumed, on this subject, in the body of the work (*9), are the following:

(1) : φx . É . ($z) . φz

(2) : φx v φy . É . ($z) . φz,

i.e. if either φx is true, or φy is true, then ($z) . φz is true. (On the necessity for this primitive proposition, see remarks on *9'11 in the body of the work.)

(3) If we can assert φy, where y is a real variable, then we can assert    (x) . φx; i.e. what holds of any, however chosen, holds of all.

Script: Bob Haney  Pencils and Inks: Bernard Baily. ™ © Respective copyright/trademark holders.

In tribal Indian cultures, before European contact, great general continuity of experience and understanding existed of each individual’s place in the world they inhabited.  Certainly this was true within the tribe, and largely between tribes within a given region. The region containing the range of a tribe held great importance for its relation to the identity of every individual. It was understood by all, that the resources of any region were finite, and to be husbanded so that all could share as needed, not just for the family or tribe, but for the resources themselves. For all plants, animals, reptiles, fish and even minerals were living beings with spirits to themselves that were equally sacred as the lives of human beings.
There is evidence that these shared values and perceptions were virtually universal across the continent, allowing of course, for regional and tribal variations. This simplicity and homogenous set of experiences, beliefs and understandings allowed the Indian people to live an existence that includes what I have termed 4D thought, that is, a broad shared set of knowledge that allowed everyone to know the world they lived in and to clearly see how they could fit into it. Language was useful of course, but it was not called upon to convey commercial or technical complexities, rhetoric beyond story, or separation of classes.
The evolution of metaphysical principals, such as those examined in this blog, are valiant attempts to bring order the dissipated perceptions of European language based thought predicated by language in practically every aspect of life. As we contiue, this will become quite apparent I hope.
Script: ?  Pencils: Dick Beck  Inks: Don Perlin ?  © Respective copyright holders.
hanBLOGlaka
Logical Philosophy In American Indian
thought and Perception
Harold R. (Hal) Foster’s Prince Valiant
© Respective copyright/trademark holders.

Wednesday, September 12, 2012

11. Ambiguous Assertion and the Real Variable

Harold R. (Hal) Foster’s Prince Valiant
© Respective copyright/trademark holders.
 

Ambiguous assertion and the real variable

Any value "x" of the function φx^ can be asserted. Such an assertion of an ambiguous member of the values of φx is symbolized by

. φx

Ambiguous assertion of this kind is a primitive idea, and cannot be defined in terms of the assertion of propositions. This primitive idea is the one which embodies the use of the variable. Apart from ambiguous assertion, the consideration of “φx,” which is an ambiguous member of the values of φx^, would be of little consequence. When we are considering or asserting "φx," the variable x is called a "real variable." Take, for example, the law of excluded middle in the form which it has in traditional formal logic:

" a is either b or not b."

Here a and b are real variables: as they vary, different propositions are expressed, though all of them are true. While a and b are undetermined, as in the above enunciation, no one definite proposition is asserted, but what is asserted is any value of the propositional function in question. This can only be legitimately asserted if, whatever value may be chosen, that value is true, i.e. if all the values are true. Thus the above form of the law of excluded middle is equivalent to

" (a, b). a is either b or not b,"

i.e. to "it is always true that a is either b or not b." But these two, though equivalent, are not identical, and we shall find it necessary to keep them distinguished.

When we assert something containing a real variable, as in e.g.

" . x=x,

we are asserting any value of a propositional function. When we assert something containing an apparent variable, as in

". (x) . x=x"  or

" . ($x) . x = x,

we are asserting, in the first case all values, in the second case some value (undetermined), of the propositional function in question.

It is plain that we can only legitimately assert "any value" if all values are true; for otherwise, since the value of the variable remains to be determined, it might be so determined as to give a false proposition. Thus in the above instance, since we have

. x=x   we may infer

. (x) . x=x.

And generally, given an assertion containing a real variable x, we may transform the real variable into an apparent one by placing the x in brackets at the beginning, followed by as many dots as there are after the assertion sign.

When we assert something containing a real variable, we cannot strictly be said to be asserting a proposition, for we only obtain a definite proposition by assigning a value to the variable, and then our assertion only applies to one definite case, so that it has not at all the same force as before. When what we assert contains a real variable, we are asserting a wholly undetermined one of all the propositions that result from giving various values to the variable. It will be convenient to speak of such assertions as asserting a propositional function. The ordinary formulae of mathematics contain such assertions; for example

" sin2 x + cos2 x = 1"

does not assert this or that particular case of the formula, nor does it assert that the formula holds for all possible values of x, though it is equivalent to this latter assertion; it simply asserts that the formula holds, leaving x wholly undetermined; and it is able to do this legitimately, because, however x may be determined, a true proposition results. Although an assertion containing a real variable does not, in strictness, assert a proposition, yet it will be spoken of as asserting a proposition except when the nature of the ambiguous assertion involved is under discussion.
Script, Pencils and Inks: Henry Boltinoff  Superturtle™ © Respective copyright/trademark holders. 
 
This post goes right to the heart of the difficulty of language and rhetoric in modern life, that of being sure of the truth of what we are expressing, or even thinking, when it comes to complex and abstract thought and ideas. Even combining a number of simple, elemental ideas everyone can agree are true, one soon reaches complexities of divergence, where agreement becomes problematic. As we wish to examine problems that are regarding one, or some number of complex propositions; ones that may be general or specific, or a combination of both, this task is quite possible for an ordered mind to undertake. A more difficult undertaking is to express any results of our calculations to others, perhaps even to ourselves, in a concise, meaningful and coherent fashion. Verbally or even in writing, the use of language is always painfully inadequate to the purpose of expressing, let alone proving complex abstract propositions to another person.

In the end, any acceptance or rejection of plans based on such propositions is, in the end, partially or mostly based on emotion, intuition, affection, dislike or any number of other reasons unrelated to the data presented. Not that the audience is incapable of understanding the plan, or even that the author is inadequate in expressing it; the problem lies with the nexus of the meeting of expression and comprehension by means of language.

We are taking in the precepts that will in total allow the consideration and expression of any complexity or multiple wildly diverse complexities to any purpose in equation-al form that clearly displays any error in their constitution for all to see, the author of the plan included; and by this means others can benefit by understanding the equations, and they in turn may act as a guide to translate the complexity accurately into language.


 Script: Carl Wessler  Pencils and Inks: Bernard Krigstein  © Respective copyright/trademark holders.
 
Harold R. (Hal) Foster’s Prince Valiant
© Respective copyright/trademark holders.
hanBLOGlaka
Logical Philosophy In American Indian
thought and Perception