User talk:R.e.s.

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[edit] Welcome from Redwolf24

Welcome!

Hello, and welcome to Wikipedia. Thank you for your contributions. I hope you like the place and decide to stay. We as a community are glad to have you and thank you for creating a user account! Here are a few good links for newcomers:

Yes some of the links appear a bit boring at first, but they are VERY helpful if you ever take the time to read them.

Remember to place any articles you create into a category so we don't get orphans.

I hope you enjoy editing here and being a Wikipedian! By the way, please be sure to sign your name on Talk and vote pages using four tildes (~~~~) to produce your name and the current date, or three tildes (~~~) for just your name. If you have any questions, see the help pages, add a question to the village pump or ask me on my Talk page. Again, welcome.

Redwolf24 (Talk) 00:13, 23 July 2005 (UTC) The current date and time is 15 June 2008 T 06:10 UTC.

P.S. I like messages :-P

Hi Redwolf24, and thanks for the welcome! The links are proving useful, and the phtml on your page is interesting too ;o)
--r.e.s. 16:04:25, 2005-07-23 (UTC)

[edit] Help with "Turing's Proof" page

Hi, I could use some edit help with the "Turing's Proof" page, especially "proof #3". (This page is meant to be interpretive, synoptic, i.e. I don't consider it "original work"). wvbaileyWvbailey 17:17, 25 January 2006 (UTC)

[edit] Turing completeness

You reverted my copyediting of Turing completeness but did not stated why in the edit summary. So.. why? Cheers, —Ruud 21:50, 14 February 2006 (UTC)

P.S. you might be interested in Wikipedia:WikiProject Computer science. —Ruud 21:52, 14 February 2006 (UTC)
P.P.S. I guess it was the misspelling of abstract machine. —Ruud 21:54, 14 February 2006 (UTC)

[edit] wvbailey here: I have a cc of Wang (1957) in pdf format, etc.

I have a cc of Wang (1957) A Variant to Turing's Theory of Computing Machines in pdf format. If you send me your e-mail address I will try to forward it to you. Also, I have an exerpted part of the first Davis paper. I was slightly in error -- it refers to Post-Turing programs on Turing machines. Oh well, what he calls a Post-Turing program is exactly what we think it is, excepting no STOP/HALT (!) He uses the same stop method I proposed to CMummert -- an instruction looping back to itself. I am going to try to use my copier to scan this, we'll see how that goes. If successful I could e-mail you that too. You can e-mail me at pierab@aol.com. wvbaileyWvbailey 18:56, 29 July 2006 (UTC)

[edit] new article: Wang B-machine

Hi, wvbailey here. I created a new article called Wang B-machine and a rediret-page called Wang machine B. Since you are the one who found this Wang-dude's reference, I say: edit to your heart's content! We could call it the Wang B model or Wang model B or whatever. If you want to move things around so Wang B-machine redirects to "Wang machine B" do whatever you want. I just picked B-machine because I liked the sound.

I did find a spiffy quote from Minsky (1967) page 200 that emphatically verifies your assertion that Wang was the first to model the Turing machine as a computer-like machine.

I've convinced myself that only one "conditional transfer" is necessary. That no "erase" is necessary is more remarkable. wvbaileyWvbailey 19:09, 23 August 2006 (UTC)

[edit] Large numbers

Hi; I moved your comment to Talk:Large numbers. Tom Harrison Talk 13:33, 14 October 2006 (UTC)

-- Thanks for moving it where it belongs. Sorry for the mix-up. --r.e.s. 19:30, 14 October 2006 (UTC)

[edit] Bijective base-k numeration

I posted this question on the talk page, but no one has answered, so I came to the original author of the page. Suppose that one changes the association of the numeral when changing sides of the decimal place, such that .A == .01 and .A9 == .001 . Would this solve the problem of there being an infinite number of ways to express a number?

Short answer, as I see it: Yes, but the system is not bijective (e.g., still 1 = .A) and it can't represent most real numbers (e.g. irrationals). I've replied to your [original posting] in more detail.--r.e.s. 19:31, 17 April 2007 (UTC)

[edit] kolmogorov complexity

Dear R.e.s.,

I'm a math student and I'd love to ask you a quick question. I noticed your participation on the k.c. page and I'm confused:

By the definition of computable function it looks as though if there exists an algorithm for computing the function that's all "computable" means. Give me a (well formed) string X, I compare it to each of the (well formed) 255 letters (or whatever) in my symbolic alphabet and conclude it is equivalent to none of them, hence its complexity exceeds 1. I can do this until I have an expression that is equivalent to X, at which point it's complexity has been computed, can't I?

I feel like I am making a common error, but can't see it. Can you help me straighten it out? Thanks,

A.M. —Preceding unsigned comment added by MotherFunctor (talk • contribs) 09:11, 8 November 2007 (UTC)

Yes, to say a function is (total) computable is just to say there is an algorithm that computes it. But no, there can be no algorithm such as you describe, if I'm understanding you correctly. The reason is that it can't complete all the comparisons you're wanting it to do: "comparing" successive strings (programs) P to the given string X, and supposedly determining in each case if P is "equivalent" to X, i.e. whether program P returns (outputs) X. If the procedure could do all of this, then the length of the first such P it found would indeed be the desired complexity of X. (In other words, the idea is the same as ordering all programs in shortlex order, simulating the execution of each one in succession, and returning the length of the first one that outputs X.) This idea won't work, because non-halting programs P will be encountered, preventing the procedure from halting; and this can't be overcome by some clever weeding-out of the non-halting programs, because the Halting Problem is undecidable.--r.e.s. 14:31, 8 November 2007 (UTC)