Re: The seven step-Mathematical preliminaries

2009-06-17 Thread Quentin Anciaux
2009/6/17 Torgny Tholerus tor...@dsv.su.se: Bruno Marchal skrev: Torgny, I agree with Quentin. You are just showing that the naive notion of set is inconsistent. Cantor already knew that, and this is exactly what forced people to develop axiomatic theories. So depending on which theory of

Re: The seven step-Mathematical preliminaries

2009-06-17 Thread Torgny Tholerus
Bruno Marchal skrev: Torgny, I agree with Quentin. You are just showing that the naive notion of set is inconsistent. Cantor already knew that, and this is exactly what forced people to develop axiomatic theories. So depending on which theory of set you will use, you can or cannot

Re: The seven step-Mathematical preliminaries

2009-06-16 Thread Bruno Marchal
Torgny, I agree with Quentin. You are just showing that the naive notion of set is inconsistent. Cantor already knew that, and this is exactly what forced people to develop axiomatic theories. So depending on which theory of set you will use, you can or cannot have an universal set (a set

Re: The seven step-Mathematical preliminaries

2009-06-14 Thread Bruno Marchal
On 12 Jun 2009, at 17:16, A. Wolf wrote: We agree then. Yes, it's my fault for creating a semantics argument. I'm usually too busy to even read the list...every once in a while something pops up and I feel obliged to comment even when it's the middle of a conversation. No

Re: The seven step-Mathematical preliminaries

2009-06-14 Thread Bruno Marchal
On 12 Jun 2009, at 20:31, Jesse Mazer wrote: Even for just an arithmetical realist. (All mathematicians are arithmetical realist, much less are mathematical realist. I am not an arithmetical realist). I assume you meant to write I am not a mathematical realist? Yes. OK, but this

Re: The seven step-Mathematical preliminaries

2009-06-14 Thread Quentin Anciaux
2009/6/14 Torgny Tholerus tor...@dsv.su.se: Quentin Anciaux skrev: Well it is illegal regarding the rules meaning with these rules set B does not exist as defined. What is it that makes set A to exist, and set B not to exist?  What is the (important) differences between the definition of

Re: The seven step-Mathematical preliminaries

2009-06-13 Thread Quentin Anciaux
2009/6/13 Torgny Tholerus tor...@dsv.su.se: Jesse Mazer skrev: Date: Fri, 12 Jun 2009 18:40:14 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries It is, as I said above, for me and all other humans to understand

Re: The seven step-Mathematical preliminaries

2009-06-13 Thread Torgny Tholerus
Quentin Anciaux skrev: 2009/6/13 Torgny Tholerus tor...@dsv.su.se: What do you think about the following deduction? Is it legal or illegal? --- Define the set A of all sets as: For all x holds that x belongs to A if and only if x is a set. This is an general rule

Re: The seven step-Mathematical preliminaries

2009-06-13 Thread Quentin Anciaux
Well it is illegal regarding the rules meaning with these rules set B does not exist as defined. 2009/6/13 Torgny Tholerus tor...@dsv.su.se: Quentin Anciaux skrev: 2009/6/13 Torgny Tholerus tor...@dsv.su.se: What do you think about the following deduction?  Is it legal or illegal?

RE: The seven step-Mathematical preliminaries

2009-06-13 Thread Jesse Mazer
Date: Sat, 13 Jun 2009 11:05:22 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Jesse Mazer skrev: Date: Fri, 12 Jun 2009 18:40:14 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com

Re: The seven step-Mathematical preliminaries

2009-06-12 Thread A. Wolf
There, they call arithmetic soundness what me (and many logician) call soundness, when they refer to theories about numbers. Like Mendelson I prefer to use the term logically valid, to what you call soundness. I may have misstated myself, but the wiki article you pointed me to agrees with

Re: The seven step-Mathematical preliminaries

2009-06-12 Thread Bruno Marchal
On 11 Jun 2009, at 21:43, Jesse Mazer wrote: Countably infinite does not mean recursively countably infinite. This is something which I will explain in the seventh step thread. There is theorem by Kleene which links Post-Turing degrees of unsolvability with the shape of arithmetical

Re: The seven step-Mathematical preliminaries

2009-06-12 Thread Bruno Marchal
Le 12-juin-09, à 09:31, Bruno Marchal a écrit : On 11 Jun 2009, at 21:43, Jesse Mazer wrote: Ah, that makes sense--I hadn't thought of combining multiple universal quantifiers in that way, but obviously you can do so and get a meaningful statement about arithmetic that for a

Re: The seven step-Mathematical preliminaries

2009-06-12 Thread Bruno Marchal
Le 12-juin-09, à 08:28, A. Wolf a écrit : There, they call arithmetic soundness what me (and many logician) call soundness, when they refer to theories about numbers. Like Mendelson I prefer to use the term logically valid, to what you call soundness. I may have misstated myself,

Re: The seven step-Mathematical preliminaries

2009-06-12 Thread A. Wolf
Logicians from different fields use terms in different ways. In provability logic and in recursion theory, soundness means often arithmetical soundness. I understand. Part of the reason for my particular viewpoint: there's a group of professors at the college I work at who are working on

Re: The seven step-Mathematical preliminaries

2009-06-12 Thread Torgny Tholerus
Jesse Mazer skrev: Date: Wed, 10 Jun 2009 09:18:10 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Jesse Mazer skrev: Date: Tue, 9 Jun 2009 18:38:23 +0200 From: tor...@dsv.su.se To: everything-list

RE: The seven step-Mathematical preliminaries

2009-06-12 Thread Jesse Mazer
Date: Fri, 12 Jun 2009 18:40:14 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Jesse Mazer skrev: Date: Wed, 10 Jun 2009 09:18:10 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com

RE: The seven step-Mathematical preliminaries

2009-06-12 Thread Jesse Mazer
From: marc...@ulb.ac.be To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Date: Fri, 12 Jun 2009 09:31:46 +0200 On 11 Jun 2009, at 21:43, Jesse Mazer wrote: Countably infinite does not mean recursively countably infinite. This is something which I

RE: The seven step-Mathematical preliminaries

2009-06-11 Thread Bruno Marchal
On 10 Jun 2009, at 20:00, Brent Meeker wrote: Bruno Marchal wrote: On 10 Jun 2009, at 02:20, Brent Meeker wrote: I think Godel's imcompleteness theorem already implies that there must be non-unique extensions, (e.g. maybe you can add an axiom either that there are infinitely many

Re: The seven step-Mathematical preliminaries

2009-06-11 Thread Bruno Marchal
On 10 Jun 2009, at 20:17, Jesse Mazer wrote: From: marc...@ulb.ac.be To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Date: Wed, 10 Jun 2009 18:03:26 +0200 On 10 Jun 2009, at 01:50, Jesse Mazer wrote: Such an hypercomputer is just what Turing

Re: The seven step-Mathematical preliminaries

2009-06-11 Thread A. Wolf
As I said, you can formalize the notion of soundness in Set Theory. But this adds nothing, except that it shows that the notion of soundness has the same level of complexity that usual analytical or topological set theoretical notions. So you can also say that unsound means violation

Re: The seven step-Mathematical preliminaries

2009-06-11 Thread Bruno Marchal
On 11 Jun 2009, at 14:48, A. Wolf wrote: As I said, you can formalize the notion of soundness in Set Theory. But this adds nothing, except that it shows that the notion of soundness has the same level of complexity that usual analytical or topological set theoretical notions.

Re: The seven step-Mathematical preliminaries

2009-06-11 Thread Brent Meeker
A. Wolf wrote: As I said, you can formalize the notion of soundness in Set Theory. But this adds nothing, except that it shows that the notion of soundness has the same level of complexity that usual analytical or topological set theoretical notions. So you can also say that unsound

Re: The seven step-Mathematical preliminaries

2009-06-10 Thread Torgny Tholerus
Jesse Mazer skrev: Date: Tue, 9 Jun 2009 18:38:23 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries For you to be able to use the word all, you must define the domain of that word. If you do not define

Re: The seven step-Mathematical preliminaries

2009-06-10 Thread John Mikes
-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries My philosophical argument is about the mening of the word all. To be able to use that word, you must associate it with a value set. What's a value set? And why do you say we must associate it in this way

Re: The seven step-Mathematical preliminaries

2009-06-10 Thread Bruno Marchal
On 10 Jun 2009, at 01:50, Jesse Mazer wrote: Isn't this based on the idea that there should be an objective truth about every well-formed proposition about the natural numbers even if the Peano axioms cannot decide the truth about all propositions? I think that the statements that

Re: The seven step-Mathematical preliminaries

2009-06-10 Thread Bruno Marchal
On 10 Jun 2009, at 02:20, Brent Meeker wrote: I think Godel's imcompleteness theorem already implies that there must be non-unique extensions, (e.g. maybe you can add an axiom either that there are infinitely many pairs of primes differing by two or the negative of that). That would seem

Re: The seven step-Mathematical preliminaries

2009-06-10 Thread Bruno Marchal
On 10 Jun 2009, at 04:14, Jesse Mazer wrote: I think I remember reading in one of Roger Penrose's books that there is a difference between an ordinary consistency condition (which just means that no two propositions explicitly contradict each other) and omega-consistency--see

Re: The seven step-Mathematical preliminaries

2009-06-10 Thread Brent Meeker
Bruno Marchal wrote: On 10 Jun 2009, at 02:20, Brent Meeker wrote: I think Godel's imcompleteness theorem already implies that there must be non-unique extensions, (e.g. maybe you can add an axiom either that there are infinitely many pairs of primes differing by two or the negative

RE: The seven step-Mathematical preliminaries

2009-06-10 Thread Jesse Mazer
Date: Wed, 10 Jun 2009 09:18:10 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Jesse Mazer skrev: Date: Tue, 9 Jun 2009 18:38:23 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re

RE: The seven step-Mathematical preliminaries

2009-06-10 Thread Jesse Mazer
From: marc...@ulb.ac.be To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Date: Wed, 10 Jun 2009 18:03:26 +0200 On 10 Jun 2009, at 01:50, Jesse Mazer wrote: Isn't this based on the idea that there should be an objective truth about every well-formed

Re: The seven step-Mathematical preliminaries

2009-06-10 Thread Bruno Marchal
Of course, Torgny stops, in the UD Argument, at step 0. He disbelieves classical computationalism. The yes doctor is made senseless; because he is a zombie, and Church thesis becomes senseless, because he is ultrafinitist, and Church thesis concerns functions from N to N, or from N to 2,

Re: The seven step-Mathematical preliminaries

2009-06-09 Thread Torgny Tholerus
Jesse Mazer skrev: Date: Sat, 6 Jun 2009 21:17:03 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries My philosophical argument is about the mening of the word all. To be able to use that word, you must associate

Re: The seven step-Mathematical preliminaries

2009-06-09 Thread Quentin Anciaux
2009/6/9 Torgny Tholerus tor...@dsv.su.se: Jesse Mazer skrev: Date: Sat, 6 Jun 2009 21:17:03 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries My philosophical argument is about the mening of the word all

Re: The seven step-Mathematical preliminaries

2009-06-09 Thread Brent Meeker
Quentin Anciaux wrote: 2009/6/9 Torgny Tholerus tor...@dsv.su.se: Jesse Mazer skrev: Date: Sat, 6 Jun 2009 21:17:03 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries My philosophical argument is about

Re: The seven step-Mathematical preliminaries

2009-06-09 Thread Quentin Anciaux
Meeker meeke...@dslextreme.com: Quentin Anciaux wrote: 2009/6/9 Torgny Tholerus tor...@dsv.su.se: Jesse Mazer skrev: Date: Sat, 6 Jun 2009 21:17:03 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries My philosophical

Re: The seven step-Mathematical preliminaries

2009-06-09 Thread Brian Tenneson
: Re: The seven step-Mathematical preliminaries My philosophical argument is about the mening of the word all. To be able to use that word, you must associate it with a value set. What's a value set? And why do you say we must associate it in this way? Do you have a philosophical

Re: The seven step-Mathematical preliminaries

2009-06-09 Thread Quentin Anciaux
Meeker meeke...@dslextreme.com: Quentin Anciaux wrote: 2009/6/9 Torgny Tholerus tor...@dsv.su.se: Jesse Mazer skrev: Date: Sat, 6 Jun 2009 21:17:03 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries My philosophical

Re: The seven step-Mathematical preliminaries

2009-06-09 Thread Brent Meeker
Quentin Anciaux wrote: You have to explain why the exception is needed in the first place... The rule is true until the rule is not true anymore, ok but you have to explain for what sufficiently large N the successor function would yield next 0 and why or to add that N and that exception to

RE: The seven step-Mathematical preliminaries

2009-06-09 Thread Jesse Mazer
Date: Tue, 9 Jun 2009 18:38:23 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Jesse Mazer skrev: Date: Sat, 6 Jun 2009 21:17:03 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re

Re: The seven step-Mathematical preliminaries

2009-06-09 Thread Quentin Anciaux
2009/6/9 Brent Meeker meeke...@dslextreme.com: Quentin Anciaux wrote: You have to explain why the exception is needed in the first place... The rule is true until the rule is not true anymore, ok but you have to explain for what sufficiently large N the successor function would yield next

Re: The seven step-Mathematical preliminaries

2009-06-09 Thread Quentin Anciaux
2009/6/9 Quentin Anciaux allco...@gmail.com: 2009/6/9 Brent Meeker meeke...@dslextreme.com: Quentin Anciaux wrote: You have to explain why the exception is needed in the first place... The rule is true until the rule is not true anymore, ok but you have to explain for what sufficiently

Re: The seven step-Mathematical preliminaries

2009-06-09 Thread George Levy
A good model of the naturalist math that Torgny is talking about is the overflow mechanism in computers. For example in a 64 bit machine you may define overflow for positive integers as 2^^64 -1. If negative integers are included then the biggest positive could be 2^^32-1. Torgny would also

RE: The seven step-Mathematical preliminaries

2009-06-09 Thread Jesse Mazer
Date: Tue, 9 Jun 2009 12:54:16 -0700 From: meeke...@dslextreme.com To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries You don't justify definitions. How would you justify Peano's axioms as being the right ones? You are just confirming my

Re: The seven step-Mathematical preliminaries

2009-06-09 Thread Brent Meeker
Jesse Mazer wrote: Date: Tue, 9 Jun 2009 12:54:16 -0700 From: meeke...@dslextreme.com To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries You don't justify definitions. How would you justify Peano's axioms as being the right ones? You

Re: The seven step-Mathematical preliminaries

2009-06-09 Thread Quentin Anciaux
2009/6/10 Brent Meeker meeke...@dslextreme.com: Jesse Mazer wrote: Date: Tue, 9 Jun 2009 12:54:16 -0700 From: meeke...@dslextreme.com To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries You don't justify definitions. How would you justify

RE: The seven step-Mathematical preliminaries

2009-06-09 Thread Jesse Mazer
Date: Tue, 9 Jun 2009 15:22:10 -0700 From: meeke...@dslextreme.com To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Jesse Mazer wrote: Date: Tue, 9 Jun 2009 12:54:16 -0700 From: meeke...@dslextreme.com To: everything-list@googlegroups.com

Re: The seven step-Mathematical preliminaries

2009-06-09 Thread Brent Meeker
Jesse Mazer wrote: Date: Tue, 9 Jun 2009 15:22:10 -0700 From: meeke...@dslextreme.com To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Jesse Mazer wrote: Date: Tue, 9 Jun 2009 12:54:16 -0700 From: meeke...@dslextreme.com

RE: The seven step-Mathematical preliminaries

2009-06-09 Thread Jesse Mazer
Date: Tue, 9 Jun 2009 17:20:39 -0700 From: meeke...@dslextreme.com To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Jesse Mazer wrote: Date: Tue, 9 Jun 2009 15:22:10 -0700 From: meeke...@dslextreme.com To: everything-list@googlegroups.com

Re: The seven step-Mathematical preliminaries

2009-06-07 Thread russell standish
On Sat, Jun 06, 2009 at 10:22:11AM -0700, Brent Meeker wrote: I wonder if anyone has tried work with a theory of finite numbers: where BIGGEST+1=BIGGEST or BIGGEST+1=-BIGGEST as in some computers? Brent The numbers {0,...,p-1} with p prime, and addition and multiplication given modulo p

Re: The seven step-Mathematical preliminaries 2

2009-06-07 Thread Bruno Marchal
Marty, On 07 Jun 2009, at 02:03, Brent Meeker wrote: m.a. wrote: *Okay, so is it true to say that things written in EXTENSION are never in formula style but are translated into formulas when we put them into INTENSION form? You can see that my difficulty with math arises from an

Re: The seven step-Mathematical preliminaries 2

2009-06-07 Thread m.a.
: Re: The seven step-Mathematical preliminaries 2 m.a. wrote: *Okay, so is it true to say that things written in EXTENSION are never in formula style but are translated into formulas when we put them into INTENSION form? You can see that my difficulty with math arises from an inability

Re: The seven step-Mathematical preliminaries 2

2009-06-07 Thread m.a.
Bruno, Yes, this seems very clear and will be helpful to refer back to if necessary. m.a. - Original Message - From: Bruno Marchal marc...@ulb.ac.be To: everything-list@googlegroups.com Sent: Sunday, June 07, 2009 4:33 AM Subject: Re: The seven step-Mathematical

Re: The seven step-Mathematical preliminaries

2009-06-07 Thread John Mikes
On Sat, Jun 6, 2009 at 4:20 PM, Jesse Mazer laserma...@hotmail.com wrote: Date: Sat, 6 Jun 2009 21:17:03 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Jesse Mazer skrev: [[[ Date: Sat, 6 Jun 2009

Re: The seven step-Mathematical preliminaries 2

2009-06-07 Thread m.a.
: Bruno Marchal To: everything-list@googlegroups.com Sent: Wednesday, June 03, 2009 1:15 PM Subject: Re: The seven step-Mathematical preliminaries 2 ? ? A = ? ? B = A ? ? = B ? ? = N ? ? = B ? ? = ? ? B

Re: The seven step-Mathematical preliminaries 2

2009-06-07 Thread Bruno Marchal
: The seven step-Mathematical preliminaries 2 ∅ ∪ A = ∅ ∪ B = A ∪ ∅ = B ∪ ∅ = N ∩ ∅ = B ∩ ∅ = ∅ ∩ B = ∅ ∩ ∅ = ∅ ∪ ∅ = http://iridia.ulb.ac.be/~marchal/ --~--~-~--~~~---~--~~ You received

Re: The seven step-Mathematical preliminaries 2

2009-06-07 Thread Bruno Marchal
Marty, Kim, I realize that, now, the message I have just sent does not have the right symbols. Apparently my computer does not understand the Thunderbird! From now on I will use capital words for the mathematical symbols. And I will write mathematical expression in bold. For examples:

Re: The seven step-Mathematical preliminaries

2009-06-06 Thread Torgny Tholerus
Jesse Mazer skrev: Date: Fri, 5 Jun 2009 08:33:47 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Brian Tenneson skrev: How can BIGGEST+1 be a natural number but not belong to the set of all natural

RE: The seven step-Mathematical preliminaries

2009-06-06 Thread Jesse Mazer
Date: Sat, 6 Jun 2009 16:48:21 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Jesse Mazer skrev: Date: Fri, 5 Jun 2009 08:33:47 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re

Re: The seven step-Mathematical preliminaries

2009-06-06 Thread Brent Meeker
Torgny Tholerus wrote: Jesse Mazer skrev: Date: Fri, 5 Jun 2009 08:33:47 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Brian Tenneson skrev: How can BIGGEST+1 be a natural number but not belong

Re: The seven step-Mathematical preliminaries

2009-06-06 Thread A. Wolf
I wonder if anyone has tried work with a theory of finite numbers: where BIGGEST+1=BIGGEST or BIGGEST+1=-BIGGEST as in some computers? There is a group of faculty who address this problem directly in my department. But any general-purpose computer can emulate true, unlimited natural numbers

Re: The seven step-Mathematical preliminaries 2

2009-06-06 Thread m.a.
To: everything-list@googlegroups.com Sent: Wednesday, June 03, 2009 1:15 PM Subject: Re: The seven step-Mathematical preliminaries 2 ∅ ∪ A = ∅ ∪ B = A ∪ ∅ = B ∪ ∅ = N ∩ ∅ = B ∩ ∅ = ∅ ∩ B = ∅ ∩ ∅ = ∅ ∪ ∅ = --- To unsubscribe from this group, send email

Re: The seven step-Mathematical preliminaries

2009-06-06 Thread Torgny Tholerus
Jesse Mazer skrev: Date: Sat, 6 Jun 2009 16:48:21 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Jesse Mazer skrev: Here you're just contradicting yourself. If you say BIGGEST+1 is then a natural number

RE: The seven step-Mathematical preliminaries

2009-06-06 Thread Jesse Mazer
Date: Sat, 6 Jun 2009 21:17:03 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Jesse Mazer skrev: Date: Sat, 6 Jun 2009 16:48:21 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re

Re: The seven step-Mathematical preliminaries 2

2009-06-06 Thread Bruno Marchal
, 2009 1:15 PM Subject: Re: The seven step-Mathematical preliminaries 2 ∅ ∪ A = ∅ ∪ B = A ∪ ∅ = B ∪ ∅ = N ∩ ∅ = B ∩ ∅ = ∅ ∩ B = ∅ ∩ ∅ = ∅ ∪ ∅ = --- To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com For more options, visit

Re: The seven step-Mathematical preliminaries

2009-06-06 Thread Brent Meeker
Jesse Mazer wrote: Date: Sat, 6 Jun 2009 21:17:03 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Jesse Mazer skrev: Date: Sat, 6 Jun 2009 16:48:21 +0200 From: tor...@dsv.su.se To: everything-list

RE: The seven step-Mathematical preliminaries 2

2009-06-06 Thread Jesse Mazer
If it helps, here's a screenshot of how the symbols are supposed to look: http://img34.imageshack.us/img34/3345/picture2uzk.png From: marc...@ulb.ac.be To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries 2 Date: Sat, 6 Jun 2009 22:36:01 +0200 Marty, Bruno

Re: The seven step-Mathematical preliminaries 2

2009-06-06 Thread m.a.
Marchal To: everything-list@googlegroups.com Sent: Saturday, June 06, 2009 4:36 PM Subject: Re: The seven step-Mathematical preliminaries 2 We do have problem of symbols, with the mail. I don't see any rectangle in the message below! Take it easy and . We will go very slowly

Re: The seven step-Mathematical preliminaries 2

2009-06-06 Thread m.a.
To: everything-list@googlegroups.com Sent: Wednesday, June 03, 2009 1:15 PM Subject: Re: The seven step-Mathematical preliminaries 2 === Intension and extension In the case of finite and little set we have seen that we can define them

Re: The seven step-Mathematical preliminaries

2009-06-06 Thread Quentin Anciaux
2009/6/6 Torgny Tholerus tor...@dsv.su.se: Jesse Mazer skrev: Date: Sat, 6 Jun 2009 16:48:21 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Jesse Mazer skrev: Here you're just contradicting yourself

Re: The seven step-Mathematical preliminaries 2

2009-06-06 Thread Bruno Marchal
- From: Bruno Marchal To: everything-list@googlegroups.com Sent: Wednesday, June 03, 2009 1:15 PM Subject: Re: The seven step-Mathematical preliminaries 2 ∅ ∪ A = ∅ ∪ B = A ∪ ∅ = B ∪ ∅ = N ∩ ∅ = B ∩ ∅ = ∅ ∩ B = ∅ ∩ ∅ = ∅ ∪ ∅ = --- To unsubscribe from

Re: The seven step-Mathematical preliminaries 2

2009-06-06 Thread Bruno Marchal
expression just slip out from my mind. smaller than is much better! Thanks for helping, Bruno - Original Message - From: Bruno Marchal To: everything-list@googlegroups.com Sent: Wednesday, June 03, 2009 1:15 PM Subject: Re: The seven step-Mathematical preliminaries 2

Re: The seven step-Mathematical preliminaries 2

2009-06-06 Thread m.a.
On this date, you made the following correction: You cannot write D = 4*x ..., But you wrote D= 4*x in the exercise just above it. I don't get the distinction between your use of the equation and mine. - Original Message - From: Bruno Marchal Exercise 2: I will

Re: The seven step-Mathematical preliminaries 2

2009-06-06 Thread Brent Meeker
m.a. wrote: *Bruno,* * I've encountered some difficulty with the examples below. You say that in extension describes exhaustion or quasi-exhaustion. And you give the example: **B = {3, 6, 9, 12, ... 99}.* * Then you define in intension with exactly the same type

Re: The seven step-Mathematical preliminaries 2

2009-06-06 Thread m.a.
Bruno, When I tried to copy the symbols from the URL cited below, I found that my email server was not able to reproproduce the intersection or the union symbol. See below: From: Bruno Marchal To: everything-list@googlegroups.com ∅ ∪ A = I see two

Re: The seven step-Mathematical preliminaries

2009-06-06 Thread Brent Meeker
Quentin Anciaux wrote: 2009/6/6 Torgny Tholerus tor...@dsv.su.se: Jesse Mazer skrev: Date: Sat, 6 Jun 2009 16:48:21 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Jesse Mazer skrev: Here

Re: The seven step-Mathematical preliminaries 2

2009-06-06 Thread m.a.
Okay, so is it true to say that things written in EXTENSION are never in formula style but are translated into formulas when we put them into INTENSION form? You can see that my difficulty with math arises from an inability to master even the simplest definitions.marty a. -

Re: The seven step-Mathematical preliminaries 2

2009-06-06 Thread Brent Meeker
m.a. wrote: *Okay, so is it true to say that things written in EXTENSION are never in formula style but are translated into formulas when we put them into INTENSION form? You can see that my difficulty with math arises from an inability to master even the simplest definitions.

Re: The seven step-Mathematical preliminaries

2009-06-05 Thread Torgny Tholerus
Brian Tenneson skrev: On Thu, Jun 4, 2009 at 8:27 AM, Torgny Tholerus tor...@dsv.su.se mailto:tor...@dsv.su.se wrote: Brian Tenneson skrev: Torgny Tholerus wrote: It is impossible to create a set where the successor of every element is inside the

Re: The seven step-Mathematical preliminaries

2009-06-05 Thread Torgny Tholerus
Kory Heath skrev: On Jun 4, 2009, at 8:27 AM, Torgny Tholerus wrote: How do you handle the Russell paradox with the set of all sets that does not contain itself? Does that set contain itself or not? My answer is that that set does not contain itself, because no set can contain

Re: The seven step-Mathematical preliminaries

2009-06-05 Thread Quentin Anciaux
2009/6/5 Torgny Tholerus tor...@dsv.su.se: Kory Heath skrev: On Jun 4, 2009, at 8:27 AM, Torgny Tholerus wrote: How do you handle the Russell paradox with the set of all sets that does not contain itself?  Does that set contain itself or not? My answer is that that set does not contain

RE: The seven step-Mathematical preliminaries

2009-06-05 Thread Jesse Mazer
Date: Fri, 5 Jun 2009 08:33:47 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Brian Tenneson skrev: On Thu, Jun 4, 2009 at 8:27 AM, Torgny Tholerus tor...@dsv.su.se mailto:tor...@dsv.su.se wrote

Re: The seven step-Mathematical preliminaries

2009-06-05 Thread Brian Tenneson
Torgny Tholerus wrote: Brian Tenneson skrev: On Thu, Jun 4, 2009 at 8:27 AM, Torgny Tholerus tor...@dsv.su.se mailto:tor...@dsv.su.se wrote: Brian Tenneson skrev: Torgny Tholerus wrote: It is impossible to create a set where the successor of every

Re: The seven step-Mathematical preliminaries

2009-06-05 Thread A. Wolf
From what you said earlier, BIGGEST={0,1,...,BIGGEST-1}. Then BIGGEST+1={0,1,...,BIGGEST-1} union {BIGGEST} = {0,1,...,BIGGEST}. Why would {0,1,...BIGGEST} not be a natural number while {0,1,...,BIGGEST-1} is? If {0, 1, ... , BIGGEST-1} is a natural number, then {0,1,...,BIGGEST} is too,

Re: The seven step-Mathematical preliminaries 2

2009-06-05 Thread m.a.
10:03 AM Subject: Re: The seven step-Mathematical preliminaries 2 Hi Marty, On 05 Jun 2009, at 00:30, m.a. wrote: Bruno, I don't have dyslexia Good news. but my keyboard doesn't contain either the UNION symbol or the INTERSECTION symbol

Re: The seven step-Mathematical preliminaries

2009-06-04 Thread Torgny Tholerus
Brian Tenneson skrev: How do you know that there is no biggest number? Have you examined all the natural numbers? How do you prove that there is no biggest number? In my opinion those are excellent questions. I will attempt to answer them. The intended audience of my

Re: The seven step-Mathematical preliminaries

2009-06-04 Thread Quentin Anciaux
If you are ultrafinitist then by definition the set N does not exist... (nor any infinite set countably or not). If you pose the assumption of a biggest number for N, you come to a contradiction because you use the successor operation which cannot admit a biggest number.(because N is well

Re: The seven step-Mathematical preliminaries 2

2009-06-04 Thread kimjo...@ozemail.com.au
On Thu Jun 4 1:15 , Bruno Marchal sent: Very good answer, Kim,  Just a few comments. and then the sequel. Exercice 4: does the real number square-root(2) belongs to {0, 1, 2,   3, ...}? No idea what square-root(2) means. When I said I was innumerate I wasn't kidding! I could of

Re: The seven step-Mathematical preliminaries

2009-06-04 Thread Torgny Tholerus
Quentin Anciaux skrev: If you are ultrafinitist then by definition the set N does not exist... (nor any infinite set countably or not). All sets are finite. It it (logically) impossible to construct an infinite set. You can construct the set N of all natural numbers. But that set must

Re: The seven step-Mathematical preliminaries

2009-06-04 Thread Brian Tenneson
This is a denial of the axiom of infinity. I think a foundational set theorist might agree that it is impossible to -construct- an infinite set from scratch which is why they use the axiom of infinity. People are free to deny axioms, of course, though the result will not be like ZFC set

Re: The seven step-Mathematical preliminaries

2009-06-04 Thread Torgny Tholerus
Brian Tenneson skrev: This is a denial of the axiom of infinity. I think a foundational set theorist might agree that it is impossible to -construct- an infinite set from scratch which is why they use the axiom of infinity. People are free to deny axioms, of course, though the result will

Re: The seven step-Mathematical preliminaries

2009-06-04 Thread Brian Tenneson
Torgny Tholerus wrote: Brian Tenneson skrev: This is a denial of the axiom of infinity. I think a foundational set theorist might agree that it is impossible to -construct- an infinite set from scratch which is why they use the axiom of infinity. People are free to deny axioms, of

Re: The seven step-Mathematical preliminaries 2

2009-06-04 Thread Bruno Marchal
Hi Marty, On 04 Jun 2009, at 01:11, m.a. wrote: Bruno, I stopped half-way through because I'm not at all sure of my answers and would like to have them confirmed or corrected, if necessary, rather than go on giving wrong answers. marty a. No problem. Exercise 1: Could

Re: The seven step-Mathematical preliminaries 2

2009-06-04 Thread Jason Resch
On Thu, Jun 4, 2009 at 7:28 AM, kimjo...@ozemail.com.au kimjo...@ozemail.com.au wrote: On Thu Jun  4  1:15 , Bruno Marchal  sent: Very good answer, Kim, Just a few comments. and then the sequel. Exercice 4: does the real number square-root(2) belongs to {0, 1, 2, 3, ...}? No idea what

Re: The seven step-Mathematical preliminaries

2009-06-04 Thread Brent Meeker
I've never seen an ultrafinitist definition of the natural numbers. The usual definition via Peano's axioms obviously rules out there being a largest number. I would suppose that an ultrafinitist definition of the natural numbers would be something like seen in a computer (which is

Re: The seven step-Mathematical preliminaries

2009-06-04 Thread Brent Meeker
Torgny Tholerus wrote: Brian Tenneson skrev: This is a denial of the axiom of infinity. I think a foundational set theorist might agree that it is impossible to -construct- an infinite set from scratch which is why they use the axiom of infinity. People are free to deny axioms, of

Re: The seven step-Mathematical preliminaries

2009-06-04 Thread Bruno Marchal
On 04 Jun 2009, at 15:40, Brian Tenneson wrote: This is a denial of the axiom of infinity. I think a foundational set theorist might agree that it is impossible to -construct- an infinite set from scratch which is why they use the axiom of infinity. People are free to deny axioms, of

Re: The seven step-Mathematical preliminaries

2009-06-04 Thread Jason Resch
Torngy, How many numbers do you think exist between 0 and 1? Certainly not only the ones we define, for then there would be a different quantity of numbers between 1 and 2, or 2 and 3. Jason On Thu, Jun 4, 2009 at 10:27 AM, Torgny Tholerus tor...@dsv.su.se wrote: Brian Tenneson skrev:

Re: The seven step-Mathematical preliminaries 2

2009-06-04 Thread Bruno Marchal
Hi Kim, On 04 Jun 2009, at 14:28, kimjo...@ozemail.com.au wrote: OK - I find this quite mind-blowing; probably because I now understand it for the first time in my life. So how did it get this rather ridiculous name of square root? What's it called in French? Racine carrée.

RE: The seven step-Mathematical preliminaries

2009-06-04 Thread Jesse Mazer
Date: Thu, 4 Jun 2009 15:23:04 +0200 From: tor...@dsv.su.se To: everything-list@googlegroups.com Subject: Re: The seven step-Mathematical preliminaries Quentin Anciaux skrev: If you are ultrafinitist then by definition the set N does not exist... (nor any infinite set countably

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