Bo

Ah then, perhaps for the benefit of us ~non_farcebookers and in the
hopes of obtaining an ~open-utrality for your efforts you can find
some spot to place the paper? Eg a ~dropbox_account?

---~
http://u.tgu.ca/non_farcebookers
http://i.tgu.ca/open-utrality
http://i.tgu.ca/dropbox_account

greg
~krsnadas.org

--

from: Bo Jacoby <[email protected]>
to: "[email protected]" <[email protected]>
date: 7 June 2013 06:55
subject: Re: [Jprogramming] Finding repeated substrings

Philip, yes, but the JoJ-article does not include the proofs.

--

Fra: Philip Hunt (USA) <[email protected]>
Til: [email protected]
Sendt: 14:58 fredag den 7. juni 2013
Emne: Re: [Jprogramming] Finding repeated substrings

>Bo isn't your article on these things (readable via Google docs) in V1No.3 of 
>the J journal at this address http://www.journalofj.com/index.php/v1-no-3 and 
>in pdf form from Google here....

>https://docs.google.com/gview?url=http://journalofj.com/images/pdf/V1.No.3.pdf&chrome=true

>Phil

--

>On 6/7/2013 3:28 AM, Bo Jacoby wrote:

@ Raul. I didn't know that downloading the PDF requested your
password. Too bad. What can be done?
- Bo

--

Fra: Raul Miller <[email protected]>
Til: Programming forum <[email protected]>
Sendt: 22:19 torsdag den 6. juni 2013
Emne: Re: [Jprogramming] Finding repeated substrings

I would like to read the pdf.

But I do not feel like looking up my password.

--
Raul

--

On Thu, Jun 6, 2013 at 4:13 PM, Bo Jacoby <[email protected]> wrote:
@ Raul: Yes, one identity may have many proofs.

Why don't you want to download the PFD? What is the facebook account problem?
- Bo

--

Fra: Raul Miller <[email protected]>
Til: Programming forum <[email protected]>
Sendt: 22:01 torsdag den 6. juni 2013
Emne: Re: [Jprogramming] Finding repeated substrings

Note that you can have many proofs for the same identity.

>Also, I did not download your pdf, because I did not feel like signing into my 
>facebook account. So, for example, I do not know how your identities treat the 
>relationship between the pascal and sierpinski triangles.

--
Raul

--

On Thu, Jun 6, 2013 at 3:37 PM, Bo Jacoby <[email protected]> wrote:

>Yes, Roger, but if you exclude the special cases, the remaining number of 
>identities to learn is, practically speaking, finite.  I have a collection of 
>identities in

>http://www.academia.edu/3247833/Statistical_induction_and_prediction to 
>supplement those in Concrete Mathematics.

- Bo

--

Fra: Roger Hui <[email protected]>
Til: Programming forum <[email protected]>
Sendt: 18:41 torsdag den 6. juni 2013
Emne: Re: [Jprogramming] Finding repeated substrings

>To quote Graham, Knuth, & Patashnik, *Concrete Mathematics*, page 155:  The 
>numbers in Pascal's triangle satisfy, practically speaking, infinitely many 
>identities, so it's not too surprising that we can find some surprising 
>relationships by looking closely.

The relationship you quoted, (>:x)!y ?? +/x!i.y, can be generalized
into a theorem that I called Pascal's
Ladder<http://www.jsoftware.com/jwiki/Essays/Pascal%27s%20Ladder> (I
like that better than "Hockey Stick Theorem").

--

On Thu, Jun 6, 2013 at 9:18 AM, Bo Jacoby <[email protected]> wrote:

>The theorem that 2!y is equal to +/i.y is a special case of the more general 
>theorem that (>:x)!y   is equal to    +/x!i.y

- Bo

--

Fra: Roger Hui <[email protected]>
Til: Programming forum <[email protected]>
Sendt: 16:41 torsdag den 6. juni 2013
Emne: Re: [Jprogramming] Finding repeated substrings

>There is a proof of a very similar theorem in section 1.4 of *Notation as a 
>Tool of Thought <http://www.jsoftware.com/papers/tot.htm>*.  (The difference 
>is that index origin is 1 in the paper.)

--

On Thu, Jun 6, 2013 at 6:44 AM, Raul Miller <[email protected]>
wrote:

>Caution: this code can give an incomplete result. For example, I do not 
>believe it will find 'aabaab'. Rather than fix this, I'll defer to other 
>solutions in this thread (which I imagine properly address this issue).

>If anyone wants to take this code and fix it, the first instance of 2 -~/\ ] 
>should be replaced with a mechanism that treats all combinations of 2 (and not 
>just adjacent pairs).

>(And on that note, I Tracy Harms recently directed my attention to a page with 
>a beautiful proof that 2&! is +/@i. - that concept would be useful, here, I 
>think. I wish I had recorded the url of that page. But the gist of my thought 
>is that it should be possible to go from y and a member of i.2!y to a unique 
>pair of two numbers in the range i.y, and that might be a nice way of 
>implementing this "combinations of 2" function.)

FYI,
---
Raul
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm

Reply via email to