Robert Jasiek's Go Theory Research

[leichtloeslich]

I strongly believe my definition to be correct (ko)

Definitions cannot be correct. They may be more or less useful, but the word correct makes absolutely 0 sense in this context.

And you could use the most esoteric, abstract, counterintuitive and hard definitions imaginable, as long as they would produce useful results (read: actual non-trivial theorems), I believe many people would be inclined to learn them.

In the absence of such results, they're just definitions, formalizations of spoken language. And in my opinion (and I suspect I'm not alone here), lacking any theorems that can be derived from those definitions, they are basically useless.

[Cassandra]

There are terms for which
a) I strongly believe my definition to be correct (ko),
b) I have not seen one counter-example since I have written my definition (thickness, if understood to be generalised to include also inside thickness),
c) I try to be a bit better than a random go dictionary entry, but I am aware that more study and quite likely changes to the definition are needed (aji, if understood to be used for the bad possibility variety of the term).

For (a) and (b), counter-examples can be provided, if they exist at all. For (c), a pretty broad discussion is possible easily.

Definitions do never stand on their own, but persue a specific purpose.
In my understanding, definitions are used in general like

"For the following, J-Thickness shall be understood as ..."

with its most important element highlighted. Please note that this is NOT "J-Thickness", NEITHER what follows the "as" !!!

The "following" is a closed system (e.g. a book, or a theory), so a) follows from your internal attitude that the results of your work have to meet your very high-level requirements. This means that one can be sure that your definitions are well thought-out, and reliable. This also means that "correct" has to be understood as "consistent" inside the "following".
So, a) is NOT the problem !!!

b) follows immediately out of a). It is very unlikely -- and will happen only by accident -- that you will overlook a tiny detail within your work. This also is a result of your very high-level requirements, concerning the results of your work.
So, b) in NOT the problem !!!

The main problem is c) !!!
Your statement includes that you compare the result of your work with something OUTSIDE the "following". But what is the basis to do this ???

Have the "usual" readers of a "usual" Go dictionary complained en masse that the Go dictionary does not fulfil their needs at all ?
If so, how should another explanation help that is valid only INSIDE the "following" ?

In addition, there might be no need to have an extended, more "precise" definition of a very special subject.
Let me try to explain this using "thickness" as example, which seems to have lost parts of its meaning during its journey from Japanese to English. Please be aware that the majority of the English-speaking Go community has absolute no idea that the ship has lost some containers around Cape of Good Hope. So they do not miss anything.

An "unsettled" group that is surrounded by "already settled" ones, may be called "weak" or -- better fitting here -- "thin". It will be part of "common knowledge" that such a "thin" group is very likely to become much of a burden during the rest of the game, as well as an attractive aim for the opponent.

Let us assume that the opponent has just played the move, which settled the last of his surrounding groups.
Does it contribute much to the understanding of the position to call this -- somewhat special application of a -- move a "thick" one ?
If so, why should it contribute much to the general understanding of the game to try to develop a "generalization" of what we have just seen ? Just because it is a matter of course that -- if you wanted to have "settled" groups -- you would have to "settle" your groups.

[RobertJasiek]

leichtloeslich, when I say "my definition of ko is correct", I mean that it determines and distinguishes ko examples from non-ko examples. This is so for ALL known ko shapes and every non-ko shape I tested. There is (still) not even one counter-example to the definition of a ko that that the definition does not identify as a ko, or of a non-ko that the definition identifies as a ko.

[daal]

What does "influence stone difference" mean?

[SoDesuNe]

What does "influence stone difference" mean?

Coincidently: viewtopic.php?p=150913#p150913 : D

[hyperpape]

Nothing wrong with Robert asserting that his definition is correct. He aims to provide a precise definition which captures all the uses of a term we all feel like we understand. If he can capture them all, it is natural to say that his definition is correct. If our intuitive grasp of the concept is not sharp enough, it gets trickier, as we may not be able to decide what examples should be captured by our definition. At this point, it becomes harder to speak of an absolutely correct definition, but there may still be ways of deciding that some definitions are closer to being correct than others.

I am not sure where the case of ko falls, but my point is that there are standards for a correct definition, and it seems that Robert is aiming for them.

For more on the subject, try an article from an old professor of mine: http://plato.stanford.edu/entries/definitions/. The first section lays out several types of definition.

[uPWarrior]

leichtloeslich, when I say "my definition of ko is correct", I mean that it determines and distinguishes ko examples from non-ko examples. This is so for ALL known ko shapes and every non-ko shape I tested. There is (still) not even one counter-example to the definition of a ko that that the definition does not identify as a ko, or of a non-ko that the definition identifies as a ko.

Please don't overlook the 2nd and 3rd paragraphs of leichtloeslich post as I believe they are the most useful advice someone ever gave you in this forum.

[Bantari]

For reference:

Definitions cannot be correct. They may be more or less useful, but the word correct makes absolutely 0 sense in this context.

And you could use the most esoteric, abstract, counterintuitive and hard definitions imaginable, as long as they would produce useful results (read: actual non-trivial theorems), I believe many people would be inclined to learn them.

In the absence of such results, they're just definitions, formalizations of spoken language. And in my opinion (and I suspect I'm not alone here), lacking any theorems that can be derived from those definitions, they are basically useless.

And now:

Please don't overlook the 2nd and 3rd paragraphs of leichtloeslich post as I believe they are the most useful advice someone ever gave you in this forum.

I am not sure I agree with this. It would certainly be useful for definitions to be followed by theorems, but they don't need to be, its all a function of aim.

For example: lets look at recent JF's definition/explanation of 'honte' and compare it to RJ's definition/explanation. Since both did not come with any theorems, so according to the above, both are useless? I don't think so. They both aim at answering an implied question: When I see a word 'honte' in a pro commentary, what does it mean? In this sense, I would say both are good and useful, although we can certainly argue which is better.

For other of the definitions I see RJ posting here (Ko, nakade, etc), I see them more of stepping stones in his own research, formalized versions of what we already know, not some generally applicable and finalized papers. To me, its more like he says: look people, here is what I came up with, I find it useful for my purpose, anybody agree, disagree, lets discuss. In this sense - it is a very good thing he does, even if most of us are not interested or find the approach too formal.

[Bantari]

I strongly believe my definition to be correct (ko)

Definitions cannot be correct. They may be more or less useful, but the word correct makes absolutely 0 sense in this context.

I disagree with that in this context. What you say only applies when somebody defines a brand new concept.

For existing concepts, a definition can either reflect/formalize/agree with what we already know, or not, or only to some degree. And this degree of 'agreement' decides if the definition is correct or not, and to what extend. It is usually this 'degree of correctness' which we discuss here. If the definition is to far off the mark, we call it redefinition instead, and often frown upon that.

Example of bad (incorrect) definition (unless your furniture is really messed up):

• A 'wooden table' is a thing that is furry, has two ears, two eyes, wagging tail, and which needs to be walked every morning or it poops on the carpet.

Example of a better (more correct) definition:

• A 'puppy' is a thing that is furry, has two ears, two eyes, wagging tail, and which needs to be walked every morning or it poops on the carpet.

Hope this helps.

[RobertJasiek]

Nature of my ko definition:

Firstly, see my paper, in which I comment on the scope of understanding and the need of future research:

http://home.snafu.de/jasiek/ko.pdf

Secondly, the ko definition is not of the kind of definitions for which a theorem would map it to the members of the set of all positions, turns, komi, history bans and input rulesets. Instead the ko definition belongs to a weaker kind of definitions: the definition is successfully tested to that subset of all positions, turns, komi, history bans and input rulesets, so that the positions include all known ko shapes (i.e., having been reported somewhere and spread; for details, see the paper). It is like a theory of physics (such as the general theory of relativity viewed on the macroscopic scale excluding quantum mechanics) that has been very thoroughly tested against perceived reality without any counter-example thus far.

Future research should continue to classify all shape classes etc., so that a theorem becomes possible, or a counter-example can be found.

[uPWarrior]

For reference:
I am not sure I agree with this. It would certainly be useful for definitions to be followed by theorems, but they don't need to be, its all a function of aim.

For example: lets look at recent JF's definition/explanation of 'honte' and compare it to RJ's definition/explanation. Since both did not come with any theorems, so according to the above, both are useless? I don't think so. They both aim at answering an implied question: When I see a word 'honte' in a pro commentary, what does it mean? In this sense, I would say both are good and useful, although we can certainly argue which is better.

For other of the definitions I see RJ posting here (Ko, nakade, etc), I see them more of stepping stones in his own research, formalized versions of what we already know, not some generally applicable and finalized papers. To me, its more like he says: look people, here is what I came up with, I find it useful for my purpose, anybody agree, disagree, lets discuss. In this sense - it is a very good thing he does, even if most of us are not interested or find the approach too formal.

I obviously have no issue in stepping stones on someones research, but I thought threads in the study journal section are asking for some sort of advice (as a moderator recently noted).

Regarding the formality, I disagree. I think it is in that spot where it is not formal enough to deserve a "go theory research" label and it is too formal to be a useful definition for an amateur. Go theory research is closer to math than to enumerations.

Nature of my ko definition:

Firstly, see my paper, in which I comment on the scope of understanding and the need of future research:

http://home.snafu.de/jasiek/ko.pdf

Secondly, the ko definition is not of the kind of definitions for which a theorem would map it to the members of the set of all positions, turns, komi, history bans and input rulesets. Instead the ko definition belongs to a weaker kind of definitions: the definition is successfully tested to that subset of all positions, turns, komi, history bans and input rulesets, so that the positions include all known ko shapes (i.e., having been reported somewhere and spread; for details, see the paper). It is like a theory of physics (such as the general theory of relativity viewed on the macroscopic scale excluding quantum mechanics) that has been very thoroughly tested against perceived reality without any counter-example thus far.

Future research should continue to classify all shape classes etc., so that a theorem becomes possible, or a counter-example can be found.

The reason I think your KO definition is useless:
- A KO definition shouldn't be 46 pages long.

If a definition is 46 pages long, then it's no longer a definition but something else. Not even the most complicate english word requires 46 pages to be explained in terms of simpler building blocks.

[RobertJasiek]

uPWarrior, if you carefully read my ko paper, you would notice that the definition itself is 1 short line long. It relies on 2 pages of preparatory definitions, of which a half is repeated or enhanced earlier research. The other 44 pages are commentary and examples, which include all known ko shapes, which is necessary to demonstrate that the definition detecs all known ko shapes.

Exercise: the definition of global-ko-intersection includes one superfluous condition added for easing the reader's understanding.

[Bantari]

I obviously have no issue in stepping stones on someones research, but I thought threads in the study journal section are asking for some sort of advice (as a moderator recently noted).

Regarding the formality, I disagree. I think it is in that spot where it is not formal enough to deserve a "go theory research" label and it is too formal to be a useful definition for an amateur. Go theory research is closer to math than to enumerations.

Good points, for sure, and we can certainly discuss that sometime.
Personally, I think that the above is a matter of opinion, and yours is as valid as mine, or RJ's. Certainly no reason to invalidate posts or people.

Unless somebody made you *the* authority of what 'go theory research' is or should be. If so, please tell.

[uPWarrior]

I obviously have no issue in stepping stones on someones research, but I thought threads in the study journal section are asking for some sort of advice (as a moderator recently noted).

Regarding the formality, I disagree. I think it is in that spot where it is not formal enough to deserve a "go theory research" label and it is too formal to be a useful definition for an amateur. Go theory research is closer to math than to enumerations.

Good points, for sure, and we can certainly discuss that sometime.
Personally, I think that the above is a matter of opinion, and yours is as valid as mine, or RJ's. Certainly no reason to invalidate posts or people.

Absolutely. I don't think I did that.

[leichtloeslich]

He aims to provide a precise definition which captures all the uses of a term we all feel like we understand.

Are you sure? Have you taken a look at his definition? Afaik what "normal people" refer to as "ko", RJ would refer to as "basic ko", the definition of which is fairly trivial. See also here for a discussion along similar lines.

@Robert: could you give a short, informal description of what you are talking about when you refer to "ko"?
Preferably in terms everyone can understand without reading any of your research. (For example I think most people will have a good idea of what a "cycle" is.)

A few illustrative examples would also do.

I guess my point would be, if such an informal description is not possible, how can you claim your definition is "correct"? "Correct" in relation to what?
If such a description is possible however, then, since your formal definition cannot be used to prove anything useful, what's the purpose of this level of formality in the first place?


Either way, I'm still in favour of applying the metric of "usefulness" to definitions, as opposed to "correctness", which is usually an adjactive reserved for theorems.
I made a similar point in my original posting: your definitions can be "incorrect" and counterintuitive, but still useful, and imho that's the property we search for in a definition. An alternative word for "useful" may be "practical".