NetNews Offline 2/NetNews Offline Volume 2.iso/news/comp/sys/amiga/programmer/7461

Internet Message Format | 1996-08-05 | 12.2 KB

Path: news.tau.ac.il!usenet
From: "Avi L." <[e-mail]>
Newsgroups: comp.sys.amiga.programmer
Subject: Re: 680X0 -> PPC translator?
Date: Wed, 17 Apr 1996 11:02:27 +0300
Organization: Sapiens Tech.
Message-ID: <[e-mail]>
References: <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>
NNTP-Posting-Host: honda.sapiens.co.il
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 2.01 (WinNT; I)

Mathew Hendry wrote:
Hi Mat,

> Er, I'm not "generalizing" the theorem - it applies directly to this situation.
> Since you say in another post that you don't even know what a Turing machine
> is, you clearly don't know anything about what this theorem says. So, I refer
> you to:
>
> Turing, A. M. (1937). On computable numbers, with an application to the
> Entscheidungsproblem. Proceedings of the London Mathematical Society (ser. 2),
> 42, 230-65; a correction, 43, 544-6.
>
> Two things are significant here:
>
> 1. Current computers are equivalent to generalised Turing machines - i.e.
> anything which may be computed on a generalised Turing machine may also be
> computed on a current computer (barring storage limitations) and vice versa.

ok, but that still has no barring on this specific case. look, each problem has its own
unique solution, some don't have a solution at all at this stage that's true but
havn't been proven to have no solution at all and for this specific problem neither you
nor anybody else for that matter have given me any proof that it's impossible to implement.
i'm not saying it'll solve all situations at first, but with incremental enhancements it will
get closer and closer to that ideal limit.

>
> 2. No algorithm which can be executed on a generalised Turing machine can
> completely track the logical path of every other possible algorithm in all
> situations.

fuzzy, too fuzzy.

>
> When these two points are applied to the problem of static program
> translation, it becomes clear that, since no algorithm can completely track
> the logical path followed by all programs in all situations, no algorithm can
> reliably make the distinction between code and data which your claims imply.

i gave you the method by which i would identify these sections and yet you failed to
provide me with a possible failure scenario, according to you it would be no problem
finding one. many have tried and failed and they had very strong convictions that they
were correct yet they have failed to respond to my legitimate solutions there by ignoring
the problem altogether, meaning they raised their white flag in my eyes.

>
> Note that the proof of this includes ALL POSSIBLE ALGORITHMS which one may
> attempt to use to make the distinction - and STILL the problem is insoluble in
> the general case.

again, it may not be completely bullet-proof at the beggining but it will nevertheless
deal with all known programming paradigms quite successfully. all you are seeing as a 'major'
problem is this identification of code and data which i have already described how to solve.
the next thing you're probably going to say if i've 'synced' on your frequency  correctly
is that my proof is reasonable cuz it involves some kind of probablity, well...hey it's
a free world out there, so be it.


>
> : code and data can easily be distinguished, if a series of words makes sense
> : as a code section it's probably code and you can make sure it is by
> : deferring its translation until it is called from some place else or it
> : simply makes too much sense to be random data. for example: valid
> : jump/calls, references valid addresses, code instruction sequence maintained
> : w/o being interrupted by some data word which doesn't make sense as code.
>
> This vague hand-waving only allows you to get out of certain situations, not
> all. You can wave your hands until they fall off and yet still never reach a
> complete solution.

why the hell not, give me a possible scenario where you're sure it would fail.

>
> : what you claim suggests that not any algorithm can solve ALL situations of a
> : given problem, like how many algorithms exist for adding 2 numbers. there's
> : obviously one.
>
> That is not what the theorem says at all. Clearly some classes of problem are
> completely soluble algorithmically in the general case. What the theorem says
> is that some classes are NOT, and static translation is one of that set of
> classes. The solution of generalised Diophantine equations (which I think were
> mentioned in an earlier post) is another class of problem within this set.
>

how can you be so sure that static translation falls in the unsolvable category, what
are you god all of a sudden? please stick to reality and in reality you're wrong until
proven otherwise.

> : your inability to deal with more complex problems prevents you from seeing a
> : possible solution.
>
> There is no possible solution. I cannot see something which doesn't exist. Can
> you?

well, i'm not asking you to see anything, just provide some basis for your claim of the
impossibilty of static translation, all you've done by now is hiding behind a shield of
theorems which don't necessarily have any connection to this specific problem, if you
can't stand the heat better stay out of the kitchen i guess.

>
> : just as human can do manual translation of the code so can an algorithm.
>
> Obviously, for a PARTICULAR case. All the human has to do is encode those
> operations which [s]he has performed as an algorithm. But clearly that
> algorithm will not apply to all other programs.

what??? bare in mind that a human wrote these algorithms so these algorithms are by
definition have human logic in them and can thus be understood by humans. i'm sorry
to say that i still havn't seen any aliens writing computer programs using alien logic
system. that would be a case where (human) static translations could fail.

>
> If you want to make the stronger claim that a human can in principle (*)
> translate ANY program accurately (and you have no way of proving this), then
> it does NOT follow that an algorithm can too, because it has already been
> PROVEN that an algorithm CANNOT. What follows, instead, is that humans do not
> operate algorithmically, which is a very strong claim indeed.

humans do operate algorithmatically indeed although no one said this algorithm is by any
chance flawless, no way jose, still i don't see any connection to the problem at hand
i understand that it's easier for you to stand behind your theorems but please, unless
you can provide direct connection of these theorems on this case i strongly suggest
you stop using them, and that's true in any situation. theorems aren't proofs and don't
confuse between them, just because it aligns itself well with some situations it doesn't
mean a theorem's true for all similar cases.

>
> * - in practice, a human will make errors, but we are talking about
> principle here. In other words, a human may be intellectually CAPABLE of
> solving the problem in the general case, even though in practice [s]he may
> make mistakes, die of old age in the meantime, etc.

mistakes don't imply that it can't be done for example a child could claim that 1+1 = 3, he's
wrong of course but does that make the problem any less solvable, NO!!!

> : > Sorry, no matter how many "indirect and mysterious ways" you invent, the
> : > problem cannot be solved algorithmically for all cases. That is a mathematical
> : > truth.
> :
> : oh is that so, you speak as if ALL of the math secrets are discovered to you.
>
> Of course they aren't all "discovered to me", but that is irrelevant.

irrelevant, i don't think so, if you knew ALL and i mean ALL the secrets of the mathematics
i would go down on my knees and start worshipping you :-) i would'nt even start debating
this subject, unfortunatly, you don't know all of that and you can, as can i make mistakes
that's why the PROOF concept was indeed invented, theorems are nice for most practical cases
but don't say they're useful for all cases which you havn't even started to think about.

>
> : well you DON'T know that for sure. have you tried ALL possible solutions to
> : solve one of your undecidable problems.
>
> The proof INCLUDES all possible solutions. It therefore doesn't matter how
> many of those particular solutions *I* currently know.

yeah that's true, you can't argue with the absolute truth. if you had provided me with
a concrete proof i would shut up and say that you're undoubtably right, till then you're wrong
until proven otherwise.

>
> Do you have to add every pair of numbers to know that your algorithm for
> adding a pair of numbers is correct? No, the fact that it is correct follows
> from the construction of the number system. Likewise, the fact that a computer
> cannot reliably translate all computer programs follows from the construction
> of the computer.

the first case is true and trivial, however you'll have to provide the proof for the 2nd
claim.

>
> : i'm not eliminating the impossible, oh no, some things are definitly
> : impossible even to imagine. but you simply have no CONCRETE basis for your
> : claim. as all the others have already submitted their ideas of impossible
> : getaway situations which have successfully been dealt with by yours truely,
> : i suggest you do the same to undermine my theory.
>
> All you are doing is adding bits to your algorithm to deal with more
> situations. The point is that no matter how much you add, you cannot deal
> with ALL situations. Anybody can give you an example of a program which will
> be broken by your translator (although at this time it is difficult to be
> specific, because you haven't yet given a full description of your algorithm),
> and you can come up with an enhancement which will solve that PARTICULAR
> problem, but never ALL problems.

most changes in the world are incremental by their nature, i can't see why is that
evolutionary process so bad even though it might be slow.

>
> : > Great, try translating a program which in some circumstances attempts to
> : > execute some of its own data. You immediately have a problem - is that portion
> : > of the program code or is it data? You cannot decide, for sometimes it appears
> : > to be data, and sometimes it appears to be code. This indeterminacy remains
> : > even if the program contains no bugs, and remember, nearly all useful programs
> : > DO contain bugs.
> :
> : read above paragraphs for hints of solving this simple situation.
>
> I see nothing there which would solve it in all cases. You have made vague
> claims involving "probably", "makes sense" etc. etc., fuzzy indications of
> what algorithms you use to decide such things, and NO PROOF that they would
> work in all situations (which of course they cannot, whatever they are).

why not, if a sequence of words makes sense as code according to the given critirias then
why wouldn't it be code, if it's just random data, which you know as well as i that this
would happen 1 in a million, all we've done is randomize it again.

>
> : > You may choose to work around such problems by storing indeterminate program
> : > fragments in their original form in the translated binary. But these residual
> : > untranslated pieces will have to be handled on the fly when running the
> : > translated program. In that case, you no longer have a static translator -
> : > you have an emulator.
> :
> : no no no, no further run-time analysis is necessary. only static translation.
>
> Prove it. Again, you cannot.

i gave the proofs for all other given scenarios it'll take impractical amount of
time repeating it here again.

>
> A program such as yours would be genuinely useful, even though it can only
> work in some cases. However, your claim that it is flawless and will work in
> all cases is patently false. That is what I am taking issue with.

no, i didn't say that, it would have to go through the stages of evolution as most
other complex processes go through. nobody can foresee how software will look like
in 5-10 years from now, of course new methods for solving new problems will have to be
invented. it is a rare case where a solution is good for a long period of time w/o
being modified at all.

Avi Lev