What Makes Prime Numbers So Mysterious?

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  • #51
philiprdutton said:
I was referring to the positional "stuff" that you get out of the Peano system.

Let try this: Just ignore positional stuff in the Peano system and try to get it to produce what we are calling a "counting system." Let us say the Peano system can do many things. One of the things it can do (we hope) is just simulate the basic counting system. we have been talking about. Now, equate these two systems Once you map them, then allow the positional stuff to come back into view on the Peano side. With it comes the notion of prime but you can not impose that notion of prime back onto the basic counting system that was mapped to the peano counting system.

Still not following. What do you mean when you say you "equate the two systems"?

philiprdutton said:
Steps. How does the peano successor function produce the successor? In zero time? Does the framework allow one to talk about the successor function in terms of "steps." How does the successor function "compute" the successor of x? Is it a magical filter that pumps out numbers but does not let you look into it ?

Obviously, time is not a factor in the "ether of mathematics and abstractness" but what is preventing me from saying there are 2 steps from S(4) to S(6) ?

When you're working with the pure Peano axioms, there's noting you can say about time, space, or other complexity. If you choose a particular model of the Peano axioms, then you can talk about it.
 
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  • #52
philiprdutton said:
Is there a way to map one axiomatic system to another? Has it been done for systems that are similar? Can it be done from one simple system to a system that is more feature rich but which still simulates the simpler system?

It's done a lot, sure. A system A can be shown to be consistent relative to a (stronger) system B by constructing a model of A inside B. Kelley-Morse set theory can model ZFC (and prove its consistency too, showing that KM is actually stronger).

philiprdutton said:
What exactly does it mean to map a formal axiomatic system to SOMETHING ELSE. Is this the technique employed by Godel in his most excellent work?

Which work? Godel made several major contributions to mathematics... do you mean his Incompleteness Theorem, or perhaps his earlier Completeness Theorem?
 
  • #53
Godel's proof

CRGreathouse said:
Which work? Godel made several major contributions to mathematics... do you mean his Incompleteness Theorem, or perhaps his earlier Completeness Theorem?
I was referring to the one which states that "for any self-consistent recursive axiomatic system powerful enough to describe the arithmetic of the natural numbers (Peano arithmetic), there are true propositions about the naturals that cannot be proved from the axioms." (copied from wikipedia)
 
  • #54
philiprdutton said:
I was referring to the one which states that "for any self-consistent recursive axiomatic system powerful enough to describe the arithmetic of the natural numbers (Peano arithmetic), there are true propositions about the naturals that cannot be proved from the axioms." (copied from wikipedia)

That's the Incompleteness Theorem. I don't think his proof used the mapping technique you mention.
 
  • #55
question about mapping

CRGreathouse said:
It's done a lot, sure. A system A can be shown to be consistent relative to a (stronger) system B by constructing a model of A inside B. Kelley-Morse set theory can model ZFC (and prove its consistency too, showing that KM is actually stronger).

You said "consistent"... does that mean "equivalent?"
 
  • #56
godel mapping

CRGreathouse said:
That's the Incompleteness Theorem. I don't think his proof used the mapping technique you mention.

Well he used some kind of mathematical mapping.
 
  • #57
which proof?

CRGreathouse said:
That's the Incompleteness Theorem. I don't think his proof used the mapping technique you mention.

Sorry I am talking about the more famous of the two.

I think maybe his Godel number function is the "mapping" I am referring to. I thought it was a generic mathematics technique.
 
  • #58
philiprdutton said:
You said "consistent"... does that mean "equivalent?"

No. In fact those two are inequivalent -- and you should know the reason, since you just posted it: the Incompleteness Theorem. No sufficiently strong theory* can prove its own consistency, so since KM proves ZFC to be consistent the two can't be equal (unless one is inconsistent, in which case they're both equal to the theory "for all p, p" in which everything is true).

* Any theory containing Peano arithmetic is strong enough.
 
  • #59
philiprdutton said:
Sorry I am talking about the more famous of the two.

The Incompleteness Theorem is the more famous of the two, and it's the one you quoted. The Completeness Theorem is the one that essentially says that in first-order logic, provability <--> truth.
 
  • #60
Godel encoding

Godel encoding was used by Godel as follows: "Gödel used a system of Gödel numbering based on prime factorization. He first assigned a unique natural number to each basic symbol in the formal language of arithmetic he was dealing with."

Can I assign each natural number from the Peano system to the counting systems' statements which we have been talking about here? I want each step of the counting algorithm output to be assigned the associated natural number.

(sorry human language is making it difficult to be formal and to keep all my terms in proper context. Obviously, there is no existing association when I said "associated natural number" but you know what I mean...)
 
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  • #61
enlightening...

CRGreathouse said:
No. In fact those two are inequivalent -- and you should know the reason, since you just posted it: the Incompleteness Theorem. No sufficiently strong theory* can prove its own consistency, so since KM proves ZFC to be consistent the two can't be equal (unless one is inconsistent, in which case they're both equal to the theory "for all p, p" in which everything is true).

* Any theory containing Peano arithmetic is strong enough.

Okay, sorry for my confusion thus far. I really wanted to get close to the idea of showing that the counting system and the peano system are both using the "number line" in a "synchronized" fashion.

If each system "creates" a "number line"... and, each "number line" has the same form, then I want to equate the two systems on that basis.
 
  • #62
philiprdutton said:
Can I assign each natural number from the Peano system to the counting systems' statements which we have been talking about here? I want each step of the counting algorithm output to be assigned the associated natural number.

The only statements you have in the counting system are the natural numbers and whatever your underlying logic allows with that:

"1 is in N"
"1 is in N and 7 is in N"
"(1 is in N and 7 is in N) or 6 is not in N"

You can certainly give a Godel numbering to your counting system's statements, but I don't understand to what end you are doing that. Also, do you mean statements or just theorems? Are you including false ones like "1 is not in N"?

Also, what algorithm do you mean?
 
  • #63
philiprdutton said:
Okay, sorry for my confusion thus far. I really wanted to get close to the idea of showing that the counting system and the peano system are both using the "number line" in a "synchronized" fashion.

If each system "creates" a "number line"... and, each "number line" has the same form, then I want to equate the two systems on that basis.

Still not getting it. Let me break this down and you can help me through what I don't get.

1. Each system creates a number line.
1a. Your counting scheme creates a number line.
1b. Peano arithmetic creates a number line.
2. The Peano number line has the same form as your counting scheme's number line.
3. If two number lines have the same form, they are equivalent in some sense.

What's a number line? That is, what properties does something need before you'll call it that? Surely any sensible definition will make 1b true, but some could make 1a false.

What do you mean when you say "form"? I would think this means the two share certain properties, but which?

In what sense do you want to equate the systems? Usually this would mean that systems which fit certain properties can prove a certain collection of facts about their members, but which?
 
  • #64
form

CRGreathouse said:
Still not getting it. Let me break this down and you can help me through what I don't get.

1. Each system creates a number line.
1a. Your counting scheme creates a number line.
1b. Peano arithmetic creates a number line.
2. The Peano number line has the same form as your counting scheme's number line.
3. If two number lines have the same form, they are equivalent in some sense.

What's a number line? That is, what properties does something need before you'll call it that? Surely any sensible definition will make 1b true, but some could make 1a false.
I do not know what a number line is nor "WHEN" it gets created in relation to either system. That is why I asked about what "comes first" in Peano: the number line that we all were taught as kids or the axioms. Also, I casually referred to Peano in terms of whether or not he was biased by the notion of "number line." Maybe for fun we could talk about a "counting line" since each system can at least produce or use one. Whenever I talk of number line I am referring to that "form" which has become so damn intuitive that I can't prevent it from affecting my thinking about math in general.

CRGreathouse said:
What do you mean when you say "form"? I would think this means the two share certain properties, but which?

In what sense do you want to equate the systems? Usually this would mean that systems which fit certain properties can prove a certain collection of facts about their members, but which?

Yes. I meant that the two systems "store results" in the same "form." A linear form with "points." I want to equate the two systems in terms of how their counting features use the form. Then I would allow the peano system to fully express itself and reveal the notion of prime... but then I would be able to say that you can have your prime but not in terms of the counting features only. If you can not have the prime in terms of the counting features only then that invariably says something about not having "prime" in terms of the FORM that each systems "use" (or "create").

My hope is that I can find a simple way to prevent the millions of people who know of the "prime" numbers from attributing the notion of "prime" to the "place in the form in which that number happens to reside."

(note: in my interpretation, a number can not reside anywhere until you have defined a way to talk about that number in terms of where you stopped on the counting line in order to "arrive" there.
 
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  • #65
philiprdutton said:
Maybe for fun we could talk about a "counting line" since each system can at least produce or use one.

I would argue that your counting system can't actually count, and thus isn't a "counting line" as such. That's why knowing what you mean by form is so important to me.

philiprdutton said:
Yes. I meant that the two systems "store results" in the same "form."

But Peano arithmetic has many more true results than your counting system, and I still don't know what "form" is.

philiprdutton said:
A linear form with "points."

But the counting system of yours isn't linear, is it?

philiprdutton said:
I want to equate the two systems in terms of how their counting features use the form.

Truly, I understand almost none of the key words in this sentence: "equate", "counting features", and "form".

philiprdutton said:
(note: in my interpretation, a number can not reside anywhere until you have defined a way to talk about that number in terms of where you stopped on the counting line in order to "arrive" there.

As I understand it, your counting system does not have a way to "talk about that number in terms of where you stopped on the counting line in order to 'arrive' there".
 
  • #66
number line vrs. counting line

Here is something that I wrote which might give you insight into the madness going on in my head. :)

Everyone has some understanding of the number line. I do not know if people just simply remember what they have been taught in grade school or if they intuitively have this uncanny understanding of the number line. Somewhere in between we humans know how to count using the number line. My question is about counting. Can you count without knowing numbers? If I ask you to count to 100 you can easily do this.

What if I tell you to do the same thing again but do not use the base 10 decimal system. In fact don't use any number based system. Can you count now? Sure you can. But you will soon loose track of where you are. You will know not if you are getting close to the original number that I requested you to count to. You will not know if you have passed this number.

In this context, we have a new phenomenon. The number line is basically still there but we do not have any more reason to call it a number line. Let us call it a "counting line."

the above is from this post

With this above line of thinking, I arrived at the point where I had to use "da,da,da,da,...,da" as a way to describe what happens after you abandon all the number BASED systems.
 
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  • #67
iterate

CRGreathouse said:
I would argue that your counting system can't actually count, and thus isn't a "counting line" as such. That's why knowing what you mean by form is so important to me.

Sure, you can count using the counting system. I just never said you could interpret each position as a number in the sense of what can be done once you define a number base system.

Yes, indeed you can count with the counting system. My definition of count will have to become something like: "take another algorithmic step"

I am interested in a system that let's me move forward in the "line" and I don't care at this point about whether or not you can label each position. I know this system is going to be almost useless for most people. But if you remember that the Peano system is basically able to simulate this counting system then you can not deny that lots of stuff in mathematics is related to a counting system... .it might just be harder to recognize that fact since there are so many other things you can do with Peano like the fancy multiplication or addition.
 
  • #68
philiprdutton said:
What if I tell you to do the same thing again but do not use the base 10 decimal system. In fact don't use any number based system. Can you count now? Sure you can. But you will soon loose track of where you are. You will know not if you are getting close to the original number that I requested you to count to. You will not know if you have passed this number.

You're getting into linguistics now!*

First of all, counting is not a natural thing, and there are people who do not count (most famously the Piraha of South America). Babies and animals can spot the difference between 1, 2, 3, 4-5, 6-9, and so forth, but more particular nuances are generally the area of counting which is a human construct.

But even people who can't count can use tally sticks to record and compare numbers. Essentially every truly ancient civilization used them in some form or other: notches carved into pieces of wood or whatever was convenient. (The Inca used knots in ropes instead.)

But even people who can't count and don't use devices like tally sticks, abacuses, or the like can compare numbers by setting up bijections. Imagine you want to compare the number of sheep I have to the number you have. Just pass one of yours and one of mine through a gate until one of us has none left. If we both have none left we had the same number; otherwise the one with more left has more.

This works even if, like the Piraha, you have no abstract concept of "number".

* Fortunately I've picked that up as a hobby (having read a few textbooks on the subject recommended to me by my friend who has a degree in the field).
 
  • #69
philiprdutton said:
Sure, you can count using the counting system. I just never said you could interpret each position as a number in the sense of what can be done once you define a number base system.

Yes, indeed you can count with the counting system. My definition of count will have to become something like: "take another algorithmic step"

In the systems I give, you may suppose modus ponens is the only underlying logic.

Consider the system:
Axiom 1. A

You can take as many algorithmic steps as you like with this system:
1. A (1)
2. A (1)
3. A (1)
4. A (1)
. . .

Thus it let's you count in your terminology. Perhaps you mean taking steps that are essentially different from those before?

Consider this system:
Axiom 1. A
Axiom 2. A --> B
Axiom 3. B --> A

We can take as many algorithmic steps as you like:
1. A (1)
2. A --> B (2)
3. B (MP)
4. B --> A (3)
5. A (MP)
. . .

Alternatively:

Axiom 1. A
Axiom 2. For all x, x --> x.

1. A (1)
2. A --> A (2)
3. (A --> A) --> (A --> A) (2)
4. A --> (A --> A) (MP)
. . .

Plenty of algorithmic steps, but there's no real way to count with this one. For a more concrete system, consider forming sets:

{}
{{}}
{{}, {{}}}
{{}, {{}}, {{{}}}}
{{}, {{{}}}}
{{{}, {{{}}}}, {{}}}

Sets that are subsets of others can be said to be smaller, but some sets are incomparable -- neither is smaller. This doesn't make a "number line" so much as a web.

philiprdutton said:
I am interested in a system that let's me move forward in the "line" and I don't care at this point about whether or not you can label each position. I know this system is going to be almost useless for most people. But if you remember that the Peano system is basically able to simulate this counting system then you can not deny that lots of stuff in mathematics is related to a counting system... .it might just be harder to recognize that fact since there are so many other things you can do with Peano like the fancy multiplication or addition.

I don't think the Peano axioms simulate arithmetic; I think they define how something has to act to be arithmetic.

I see set theory as the basis for mathematics more than counting, but I'm sure a counting system could be used as an alternate basis. My field (number theory) would find that particularly natural.
 
  • #70
Here is another thought:

What is faster? Counting in binary or counting in decimal? Neither. You get there at the same rate.

Who talks about numbers faster? A people who communicate about numbers only using the binary system or a people group who communicate about numbers only using base 10. They both use the same language. If you have to listen to one of these people speak out loud as they count then who takes the longest at each number when using their own number base to communicate?

Now, if you do not use any number based system when "counting out loud" you are just going to have to make a noise over and over... "buh,buh,buh,buh,buh...buh."

What is the slowest possible way for a human to count out loud? By not using a number based system to describe what point the count is currently at. They are still counting. Just not describing it with fancy short cuts. So, number systems are basically short cuts. They are an encoding which prevents people from having to "count" when exchanging numbers verbally, on paper, or whatever.
 
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  • #71
counting: my definition

CRGreathouse said:
Thus it let's you count in your terminology. Perhaps you mean taking steps that are essentially different from those before?

YES! That is what I mean when I say "count." I am sorry I had to keep perverting the standard meaning of "count" but I felt it necessary to push the thinking as far as possible down this course of study using that term.
 
  • #72
philiprdutton said:
Who talks about numbers faster? A people who communicate about numbers only using the binary system or a people group who communicate about numbers only using base 10. They both use the same language. If you have to listen to one of these people speak out loud as they count then who takes the longest at each number?

Now, if you do not use any number based system when "counting out loud" you are just going to have to make a noise over and over... "buh,buh,buh,buh,buh...buh."

What is the slowest possible way for a human to count? By not using a number based system to describe what point the count is currently at. They are still counting. Just not describing it with fancy short cuts. So, number systems are basically short cuts. They are an encoding which prevents people from having to "count" when exchanging numbers verbally, on paper, or whatever.

All of those are number systems. You're saying that decimal is just as fast as binary, but unary is slower. I would say that unary is slower than binary for numbers greater than 1, binary is slower than decimal for numbers greater than 1, ternary is slower than decimal for numbers greater than 2, hextal is slower than decimal for numbers greater than 1295, decimal is slower than hexadecimal for numbers greater than 99999, and so on.
 
  • #73
web

CRGreathouse said:
...
...
...
This doesn't make a "number line" so much as a web.

Considering your web system: Sure I can count (my def) with it:

{}
{{}}
{{}, {{}}}
{{}, {{}}, {{{}}}}
{{}, {{{}}}}
{{{}, {{{}}}}, {{}}}

is simply as follows:

step da { }
step da,da {{}}
step da,da,da {{}, {{}}}
step da,da,da,da {{}, {{}}, {{{}}}}
step da,da,da,da,da {{}, {{{}}}}
etc... {{{}, {{{}}}}, {{}}}
 
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  • #74
philiprdutton said:
YES! That is what I mean when I say "count." I am sorry I had to keep perverting the standard meaning of "count" but I felt it necessary to push the thinking as far as possible down this course of study using that term.

So consider this system.

Axiom 1. A point exists.
Axiom 2. From any point, you may draw a 1-unit arrow down and to the left. The end of the arrow is a point.
Axiom 3. From any point, you may draw a 1-unit arrow down and to the right. The end of the arrow is a point.

The metalogic of the system is that two diagrams are equal iff they have the same arrow structure, and one diagram is larger than another iff the first contains all the arrows of the second but the two are not equal.

So "/\" > "/" > "" and "/\" > "\" > "", but not ("/" > "\") and not ("\" > "/"). The system can make many different theorems ("diagrams" in its own terminology) but they don't work like the natural numbers, or any sensible number line at all.
 
  • #75
philiprdutton said:
Considering your web system: Sure I can count (my def) with it because each statement is numbered:

But someone else could use those axioms and come up with theorems in a different order. You don't want different things to be equal to each other, do you?
 
  • #76
speed

CRGreathouse said:
All of those are number systems. You're saying that decimal is just as fast as binary, but unary is slower. I would say that unary is slower than binary for numbers greater than 1, binary is slower than decimal for numbers greater than 1, ternary is slower than decimal for numbers greater than 2, hextal is slower than decimal for numbers greater than 1295, decimal is slower than hexadecimal for numbers greater than 99999, and so on.

No. I am saying unary is the slowest of them all because unary is essentially a system where you have to count (my def) "out loud" in order to express the point where you are in the counting line.

visually:

the number of decimal 10 is viewed as:

10
but in unary it is:
...

You have some correct points about relative speeds which I missed but still, nothing is slower than unary. Unary = counting (my def)
 
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  • #77
philiprdutton said:
No. I am saying unary is the slowest of them all because unary is essential a system where you have to count "out loud" in order to express the number.

visually:

the number of decimal 10 is viewed as:

10
but in unary it is:
...

Well the standard form for decimal 10 in unary would be 1111111111, but that's beside the point. Of course both could be written with different symbols, but that's just a simple replacement issue.

philiprdutton said:
You have some correct points about relative speeds which I missed but still, nothing is slower than unary. Unary = counting (my def)

I suppose one could construct systems which are slower than unary...

I presume the equal sign above means "is a kind of"?

Where were you going with this?
 
  • #78
going somewhere

Yes my equal sign is "a kind of."

Now, we can see that both the counting system and the Peano system are unary speed systems (for practical human purposes). Essentially, the Peano system at it's CORE has a counting system (my def).

So, before you can build a Peano system you must have the counting system.

The complement (as in set theory) of the counting system within the peano system is what causes the notion of "prime"... NOT the counting system.

That is where I am trying to go.

Visually take two concentric circles. The inner circle is the counting system which is a sub feature of the Peano system. The outer circle is the whole Peano system. The complement of the inner circle is what creates the ability to talk about primes.
 
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  • #79
philiprdutton said:
That is where I am trying to go.

Visually take two concentric circles. The inner circle is the counting system which is a sub feature of the Peano system. The outer circle is the whole Peano system. The complement of the inner circle is what creates the ability to talk about primes.

That's a claim, but what you want is a proof or an example. What axioms can you remove from Peano arithmetic so it can still count but not talk about primes? I may have actually given an example of this earlier on the thread...
 
  • #80
adding prime to a system

CRGreathouse said:
That's a claim, but what you want is a proof or an example. What axioms can you remove from Peano arithmetic so it can still count but not talk about primes? I may have actually given an example of this earlier on the thread...

Actually, I did not originally care about removing pieces from the Peano system. I was originally thinking about this in terms of how to build up from scratch a basic system that did not support primes but had some commonality with a system like Peano. But now that you mention it, it would be a great exercise to see how much must be removed from Peano in order that notion of "prime" can not be supported.

We essentially are talking about two directions (top down or bottom up approaches) with the same goal: to explore "when" the notion of "prime" is added to a system (which in our discussion has been Peano.
 
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  • #81
While you create new systems, try to add to them a very desirable property than Peano's have: the ability to express very big (or infinite) objects in a finite, even very compact, space of symbols. This is what makes better a system like "1 is a number, Sa is a number if a is" than "foo is a number, foo foo is a number, foo foo foo is a number, ...", or than "1 is a number, S1 is a number, SS1 is a number, SSS1 is a number, ...".
 
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  • #82
philiprdutton said:
We essentially are talking about two directions (top down or bottom up approaches) with the same goal: to explore "when" the notion of "prime" is added to a system (which in our discussion has been Peano.

My basic answer would be when you make a system strong enough to support a discrete chain/total order, you essentially have a way to talk about divisibility and thus primality.
 
  • #83
I have some confusion here. The relation < defines a total order on R, yet that doesn't make R isomorphic to N. Without that isomorphism, you get 7 is not a prime because it is divisible by 7/2.
 
  • #84
no features please

Dodo said:
While you create new systems, try to add to them a very desirable property than Peano's have: the ability to express very big (or infinite) objects in a finite, even very compact, space of symbols. This is what makes better a system like "1 is a number, Sa is a number if a is" than "foo is a number, foo foo is a number, foo foo foo is a number, ...", or than "1 is a number, S1 is a number, SS1 is a number, SSS1 is a number, ...".

I am not interested in building a system with "very desirable property than Peano's have." I have a specific reason why I am limiting the functionality of the counting system.
 
  • #85
No problem; as long as you don't count over 100, you won't spend too much paper.

But CR has a point up there. Divisibility is actually a very basic concept, that can come from addition, not necessarily multiplication. For instance, define numbers with dots, x, xx, xxx, xxxx..., and addition as concatenation. Then define divisibility by these two axioms:
1) Every number divides itself, f.i. xxx divides xxx.
2) If b divides a, then b divides a+b. That is, if xx divides xx, then xx divides xxxx, and also xx divides xxxxxx ...
 
  • #86
talking about prime

CRGreathouse said:
My basic answer would be when you make a system strong enough to support a discrete chain/total order, you essentially have a way to talk about divisibility and thus primality.

My basic thought is that "talking about" does not mean it is a "hard asset" of the system. For example, the Peano axioms lend themselves quiet well to "algorithmic" discussions due to the successor function- it lends it self quite well to a mechanical "stepping" system. However, that doesn't mean there is any real ability for the system to "step around" on the number line. It could very well just as easily magically make the numbers "poof" into existence (since there is no notion of time constraint ).

Anyway, my question about your response is: what system is weaker than a discrete chain/total order? (also, I am not totally sure what you mean by discrete chain/total order but I have a good guess that it is something that just "ticks").
 
  • #87
divisibility

Dodo said:
No problem; as long as you don't count over 100, you won't spend too much paper.

But CR has a point up there. Divisibility is actually a very basic concept, that can come from addition, not necessarily multiplication. For instance, define numbers with dots, x, xx, xxx, xxxx..., and addition as concatenation. Then define divisibility by these two axioms:
1) Every number divides itself, f.i. xxx divides xxx.
2) If b divides a, then b divides a+b. That is, if xx divides xx, then xx divides xxxx, and also xx divides xxxxxx ...

Okay I see the problem. I want a system that just "ticks." Your system is nested ticking. In my system I don't want to do anything except be able to produce the next "tick". There is no notion of nested ticking in my system. How can this be formalized with an axiomatic system? I will just call it a ticking system. Is such a ticking system the most basic kind of axiomatic system with the least amount of feature? In such a system I think divisibility is not definable. Basically, you push off the job and definition of divisibility to the observer or user.
 
  • #88
msg

Dodo said:
No problem; as long as you don't count over 100, you won't spend too much paper.

Exactly the point I made earlier. It also helps if you do not eat very much MSG (monosodium glutamate) since it is an excitotoxin and directly attacks cells in the short term memory area of the brain making it hard to count in unary...
 
  • #89
axiomatic nesting

philiprdutton said:
Okay I see the problem. I want a system that just "ticks." Your system is nested ticking. In my system I don't want to do anything except be able to produce the next "tick". There is no notion of nested ticking in my system. How can this be formalized with an axiomatic system? I will just call it a ticking system. Is such a ticking system the most basic kind of axiomatic system with the least amount of feature? In such a system I think divisibility is not definable. Basically, you push off the job and definition of divisibility to the observer or user.

Not to get off topic but I must ask because I am so curious: Is the Peano system inherently nested? Does it have built-in nesting? Do all axiomatic systems have built-in nesting? Is nesting just coming about because of the way the system is being "used" by the "user"?
 
  • #90
I'm not sure of what you mean by "nested". I think you mean,
x, xx, xxx, xxxx... are numbers​
is "not nested", while
x is a number; also, if A is a number then Ax is a number​
is "nested". I think most people here would say both are one and the same.
 
  • #91
ticking

Dodo said:
I'm not sure of what you mean by "nested". I think you mean,
x, xx, xxx, xxxx... are numbers​
is "not nested", while
x is a number; also, if A is a number then Ax is a number​
is "nested". I think most people here would say both are one and the same.
But if the system is viewed as an algorithmic process, then how do you distinguish? Especially if we are talking about a system that only can only tick. How can we limit the expressiveness of an axiomatic system so that all you can do is "poke" it so that it "ticks". Can we have a one-to-one input/output system. Axiom systems like Peano have many ways to "input" your "statements" to make them "produce" an output. I do not know how the formal mathemticians talk about the "usage" of the axiomatic systems at this level of abstraction, but I see it with the input/output metaphor.

Nested counting is where at each step of the count, the process starts again from "one."

x 1
xx 1,2
xxx 1,2,3
xxxx 1,2,3,4
xxxxx 1,2,3,4,5
etc.I am saying why waste so much effort? Just do this:
x 1
x 2
x 3
x 4
x 5
etc.

I had to put the numbers in there for visualization but I am saying that I just want a ticking system.

Anyway, Here is my focus:
I want to define a ticking system using the axiomatic method. But, I do not want the system to do anything except tick! No nesting. Can this be done with the axiomatic system or is it too flexible at it's core such that it can not make such limitations? This is a short side study on the nature of axiomatic systems.
 
  • #92
philiprdutton said:
I am saying why waste so much effort? Just do this:
x 1
x 2
x 3
x 4
x 5

In this system, what differentiates 5 from 2? Other than the fact that they were created by different axioms? This system has no notion of order, unless you explicitly put it in, in which case you get nesting as you put it.
 
  • #93
In other words, this ticking machine seems to have no internal state. When it ticks and says 'x', there is no way of telling if it is the first 'x', the 5th or the 625th. On the other hand, if it *does* have a state, then you should consider how the state is represented, and call this representation a 'number'.
 
  • #94
differentiating

NeoDevin said:
In this system, what differentiates 5 from 2? Other than the fact that they were created by different axioms? This system has no notion of order, unless you explicitly put it in, in which case you get nesting as you put it.
Yes. It is my point. You cannot differentiate those numbers. I just put them in the post for sake of moving forth in the discussion. If you view the system as an algorithmic process, then it kind of does have order. Okay. So are you saying that using a formal axiomatic theory, I can not create a ticking system with order AND which does not provide notions of divisibility, prime, and anything else related to numbers or number bases? I am interested in the answer which is why all this time I am not concerned about cool stuff like addition or division.
 
  • #95
yes

Dodo said:
In other words, this ticking machine seems to have no internal state. When it ticks and says 'x', there is no way of telling if it is the first 'x', the 5th or the 625th. On the other hand, if it *does* have a state, then you should consider how the state is represented, and call this representation a 'number'.

You are correct in saying you can not figure out if it is the first 'x' or the 5th 'x' or the 625th 'x'. I said already that I want the user of the system to worry about that. I don't want the user of the system to expect that the system to tell them via some particular feature of the system. They just use the ticking system like a metronome (a metaphor obviously).

Let me put it this way- can there be an axiomatic version of a metronome?
 
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  • #96
internal state

Dodo said:
In other words, this ticking machine seems to have no internal state. When it ticks and says 'x', there is no way of telling if it is the first 'x', the 5th or the 625th. On the other hand, if it *does* have a state, then you should consider how the state is represented, and call this representation a 'number'.

Do axiomatic systems like Peano have internal state? Can some axiomatic systems have an internal state and others not have one?
 
  • #97
I fail to see how a system with no numbers fits in a number theory forum, but for the sake of the discussion let me provide an example. The boolean operator 'not' behaves as you want. Or, if you prefer, a function f(x) = 1 - x. But unless we begin counting time, or sequence steps, the only thing we produce is the set {0,1}, with no additional structure, operations or functionality.
 
  • #98
philiprdutton said:
Yes. It is my point. You cannot differentiate those numbers. I just put them in the post for sake of moving forth in the discussion. If you view the system as an algorithmic process, then it kind of does have order. Okay. So are you saying that using a formal axiomatic theory, I can not create a ticking system with order AND which does not provide notions of divisibility, prime, and anything else related to numbers or number bases? I am interested in the answer which is why all this time I am not concerned about cool stuff like addition or division.

You want your system to have elements ('number' which function as atoms or ur-elements) and a (presumably transitive) order on those elements, and you want to know if all systems with those properties can talk about primality in some restricted way or not? Is that right?
 
  • #99
building blocks

Dodo said:
I fail to see how a system with no numbers fits in a number theory forum, but for the sake of the discussion let me provide an example. The boolean operator 'not' behaves as you want. Or, if you prefer, a function f(x) = 1 - x. But unless we begin counting time, or sequence steps, the only thing we produce is the set {0,1}, with no additional structure, operations or functionality.

The reason is not sake of discussion. The reason is of great importance. One of the points all all this discussion is that you have built on top of something to get "numbers". The thing (stepping stone) you start with is the tick system. So, whether or not you agree with what I am doing, I really need help trying to formalize the tick system without using something that already has notions of "number". Unfortunately, that math education imposed upon us does not even begin to get into these concepts.

Look at the peano system as one holistic system or look at the Peano system in terms of modular building blocks. If you take the modular building block approach then I am saying that before you can construct numbers you have to build on top of the tick system. Therefore, it has lots to do with the topic of Number Theory.
 
  • #100
philiprdutton said:
Do axiomatic systems like Peano have internal state? Can some axiomatic systems have an internal state and others not have one?

Internal state? :confused:
 
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