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 Post subject: Re: GT territory rule
Post #61 Posted: Wed Aug 25, 2021 2:27 am 
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Cassandra wrote:
jann wrote:
W claims a chunk of territory in the center with middle B string (the one between symmetric W groups) dead. Inner and outer borders are OK and W can, even with B starting, take pass-alive control of that part of the board and capture 5 stones. Right?

There is NO "pass-alive" in Gérard's proposal of territory rules.

He really should use that instead of this 2-eye business (it is better known (among rules people), more accepted, easier to define and apply - and less ad-hoc also free from the beauty flaw of explicit mention of 2 eyes). But this is utterly irrelevant here. The issue is the same with "two-eye-formation".

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 Post subject: Re: GT territory rule
Post #62 Posted: Wed Aug 25, 2021 2:49 am 
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jann wrote:
Cassandra wrote:
jann wrote:
Click Here To Show Diagram Code
[go]$$B
$$ +---------------------------------+
$$ | O O O O O X O O . X . O O X X X |
$$ | O O O O . X O O O X O O O X . O |
$$ | O O O O O X O . O X O . O X O . |
$$ | O O O O . X O O O X O O O X X O |
$$ | O O O O O X O O O X O O O X . . |
$$ +---------------------------------+
$$[/go]

W claims a chunk of territory in the center with middle B string (the one between symmetric W groups) dead. Inner and outer borders are OK and W can, even with B starting, take pass-alive control of that part of the board and capture 5 stones. Right?

There is NO "pass-alive" in Gérard's proposal of territory rules.

He really should use that instead of this 2-eye business (it is better known (among rules people), more accepted, easier to define and apply - and free from the beauty flaw of explicit mention of 2 eyes). But this is utterly irrelevant here. The issue is the same with "two-eye-formation".

Sorry, but being "pass-alive" is NOT sufficient per se.

As a matter of course is a compound of strings, which (if it not already is) can be transformed into a formation that surrounds two points that are forbidden by the rules for the opponent to occupy -- and does not have any "DAME" (i.e. there are ONLY TWO unoccupied board points surrounded) -- "pass-alive" AFTER that transformation.

But this kind of transformation does not work the other way round, as is proved by your examplary position. The (supposed) compound of White strings in the centre of your example might be "pass-alive" as it is, but it can never ever be transformed into a compound of strings, which surrounds ONLY TWO unoccupied board points.
Your (supposed) compound of White strings as a matter of course surrounds two eye-points, but two "DAME" as well, and therefore is NO "two-eye-formation". Under Gérard's ruleset, you will be asked to prove that you can capture Black's group inside your (supposed, but fake) "two-eye-formation".

This is the reason why Gérard made the occupation of "DAME" mandatory for being able to claim "territory".
To make it unmistakably clear: A "DAME" in general is an unoccupied board point that is a SHARED liberty of one White and one Black group (/ string). Usually alive ones. However, there might be a dispute about the result of the status confirmation, and therefore, you might be asked to remove all opponent's stones inside your supposed "territory", just to make sure that your claimed territory does not include any "DAME" (in case of success, the empty points have had a value, and the asssumption of these points being "DAME" was mistaken).
In Gérard's proposed rules, this explicite capturing of opponent's stones might be part of the process to create a "two-eye-formation", but it is NOT necessary per se to claim "territory", as Gérard bans "DAME" of the "outside border" only.

--------------------

BTW, I am very sure that a concept that grounds on "pass-alive" will also have the "DAME"-issue settled, before identifying "territory".
If not, this "pass-alive" belongs to a ruleset that has "territory" also in seki (but which was explicitely excluded from the start by Gérard).

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Last edited by Cassandra on Wed Aug 25, 2021 3:16 am, edited 7 times in total.
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 Post subject: Re: GT territory rule
Post #63 Posted: Wed Aug 25, 2021 2:54 am 
Judan

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Quote:
covered by a "two-eye formation"


Such a rule needs a specification of the player whose two-eye-formation it shall be.

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 Post subject: Re: GT territory rule
Post #64 Posted: Wed Aug 25, 2021 2:58 am 
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Cassandra wrote:
The (supposed) compound of White strings in the centre of your example might be "pass-alive" as it is, but it can never ever be transformed in to compound of strings, which surrounds ONLY TWO unoccupied board points.

I'm afraid you haven't understood the example (or pass-alive).

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 Post subject: Re: GT territory rule
Post #65 Posted: Wed Aug 25, 2021 3:29 am 
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jann wrote:
Cassandra wrote:
The (supposed) compound of White strings in the centre of your example might be "pass-alive" as it is, but it can never ever be transformed in to compound of strings, which surrounds ONLY TWO unoccupied board points.

I'm afraid you haven't understood the example (or pass-alive).

I might not have understood your example, that's right. And / or draw some wrong conclusion (about the "pass-alive" status of groups).

But YOU will not have applied the concept of "pass-alive" correct.

Sensei's Library wrote:
A group is pass-alive if it keeps its alive status even if the defender continues to pass whenever the attacker makes a play.

This implies that NONE of the groups / strings in your example is "pass-alive" (as usual with EVERY seki, I suppose).

jann wrote:
take pass-alive control

does not have any entry in Sensei's Library.
Probably you might be so very kind to define what this technical term shall mean.

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 Post subject: Re: GT territory rule
Post #66 Posted: Wed Aug 25, 2021 4:04 am 
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jann wrote:
Gérard TAILLE wrote:
Black can claim for the territory in the lower right corner because the borders are OK and black is able to build a two eye formation on the territory, by beginning with the above sequence.

This is quite an issue, I'm pretty sure that is not territory in J89. This also means your whole approach is problematic:

Click Here To Show Diagram Code
[go]$$B
$$ +---------------------------------+
$$ | O O O O O X O O . X . O O X X X |
$$ | O O O O . X O O O X O O O X . O |
$$ | O O O O O X O . O X O . O X O . |
$$ | O O O O . X O O O X O O O X X O |
$$ | O O O O O X O O O X O O O X . . |
$$ +---------------------------------+
$$[/go]

W claims a chunk of territory in the center with middle B string (the one between symmetric W groups) dead. Inner and outer borders are OK and W can, even with B starting, take pass-alive control of that part of the board and capture 5 stones. Right?

an interesting example, maybe also a challenge for J2003 and/or J89 . And what would be the assessment by the "tradition of Japanese pros" ?
If I understand it correctly, S must pass (in proof), W attacks right-bottom, S captures, W approaches on the left, and S has the choice of losing the group on the right or the 5 stones on the left, in either case W can capture the black 5 stones afterwards and claim "territory" as proven.

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 Post subject: Re: GT territory rule
Post #67 Posted: Wed Aug 25, 2021 4:12 am 
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Yes, that's what I had in mind. In J89 cannot play the ko (because of the pass for ko rule), and would be safe even without that because of the "enabling" rule.

The problem with the approach of this thread - as opposed to big sister LJRG - seems to be allowing global play without looking at global consequences.

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 Post subject: Re: GT territory rule
Post #68 Posted: Wed Aug 25, 2021 4:42 am 
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Excuse me folks, but drawing diagrams would help you a lot, as well as your audience.
I know that this activity can be very painful at times, especially when you have to put the same sequence on paper for the 153rd time.
However, diagram painting enables your audience to easily understand your explanations, as well as the appearance of "Why not here?" moments with yourself.

Click Here To Show Diagram Code
[go]$$B
$$ +---------------------------------+
$$ | O O O O O Y O O T Y T O O X X X |
$$ | O O O O T Y O O O Y O O O X . O |
$$ | O O O O O Y O T O Y O T O X O . |
$$ | O O O O T Y O O O Y O O O X X O |
$$ | O O O O O Y O O O Y O O O X . . |
$$ +---------------------------------+$$[/go]

Let's this be the final position of "play", and White claiming "territory" at any of the triangled points.
=> White claims that she will be able to establish a "two-eye-formation" somewhere on the left part of the board.
=> Black has the right of moving first.

Click Here To Show Diagram Code
[go]$$B
$$ +---------------------------------+
$$ | O O O O O X O O . X . O O X X X |
$$ | O O O O . X O O O X O O O X . O |
$$ | O O O O O X O . O X O . O X O . |
$$ | O O O O . X O O O X O O O X X O |
$$ | O O O O O X O O O X O O O X 1 . |
$$ +---------------------------------+$$[/go]

Click Here To Show Diagram Code
[go]$$B
$$ +---------------------------------+
$$ | O O O O O X O O ? X ? O O X X X |
$$ | O O O O ? X O O O X O O O X ? O |
$$ | O O O O O X O ? O X O ? O X O . |
$$ | O O O O ? X O O O X O O O X X O |
$$ | O O O O O X O O O X O O O X X ? |
$$ +---------------------------------+$$[/go]

All shadowed points are self-atari.

Click Here To Show Diagram Code
[go]$$B :b3: :w4: pass
$$ +---------------------------------+
$$ | O O O O O X O O ? X ? O O X X X |
$$ | O O O O ? X O O O X O O O X ? O |
$$ | O O O O O X O ? O X O ? O X O 2 |
$$ | O O O O ? X O O O X O O O X X O |
$$ | O O O O O X O O O X O O O X X ? |
$$ +---------------------------------+$$[/go]

THE END


Variation:

Click Here To Show Diagram Code
[go]$$B
$$ +---------------------------------+
$$ | O O O O O X O O ? X ? O O X X X |
$$ | O O O O ? X O O O X O O O X ? O |
$$ | O O O O O X O ? O X O ? O X O 3 |
$$ | O O O O ? X O O O X O O O X X O |
$$ | O O O O O X O O O X O O O X X 2 |
$$ +---------------------------------+$$[/go]

Click Here To Show Diagram Code
[go]$$B
$$ +---------------------------------+
$$ | O O O O O X O O ? X ? O O X X X |
$$ | O O O O ? X O O O X O O O X ? O |
$$ | O O O O O X O ? O X O ? O X O X |
$$ | O O O O ? X O O O X O O O X X 4 |
$$ | O O O O O X O O O X O O O X X . |
$$ +---------------------------------+$$[/go]

Click Here To Show Diagram Code
[go]$$B :b5: :w6: pass
$$ +---------------------------------+
$$ | O O O O O X O O ? X ? O O X X X |
$$ | O O O O ? X O O O X O O O X ? O |
$$ | O O O O O X O ? O X O ? O X O . |
$$ | O O O O ? X O O O X O O O X X O |
$$ | O O O O O X O O O X O O O X X ? |
$$ +---------------------------------+$$[/go]

THE END

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Last edited by Cassandra on Wed Aug 25, 2021 4:52 am, edited 2 times in total.
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 Post subject: Re: GT territory rule
Post #69 Posted: Wed Aug 25, 2021 4:49 am 
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Your B 1 is bad idea, W then makes bulky five and takes entire board.

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 Post subject: Re: GT territory rule
Post #70 Posted: Wed Aug 25, 2021 5:17 am 
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jann wrote:
Gérard TAILLE wrote:
Black can claim for the territory in the lower right corner because the borders are OK and black is able to build a two eye formation on the territory, by beginning with the above sequence.

This is quite an issue, I'm pretty sure that is not territory in J89. This also means your whole approach is problematic:

Click Here To Show Diagram Code
[go]$$B
$$ +---------------------------------+
$$ | O O O O O X O O . X . O O X X X |
$$ | O O O O . X O O O X O O O X . O |
$$ | O O O O O X O . O X O . O X O . |
$$ | O O O O . X O O O X O O O X X O |
$$ | O O O O O X O O O X O O O X . . |
$$ +---------------------------------+
$$[/go]

W claims a chunk of territory in the center with middle B string (the one between symmetric W groups) dead. Inner and outer borders are OK and W can, even with B starting, take pass-alive control of that part of the board and capture 5 stones. Right?


BTW Jann, why not having "simply" use the following position:

Click Here To Show Diagram Code
[go]$$B
$$ +---------------------------+
$$ | O O X O O . X . O O X X X |
$$ | O . X O O O X O O O X . O |
$$ | O O X O . O X O . O X O . |
$$ | O . X O O O X O O O X X O |
$$ | O O X O O O X O O O X . . |
$$ +---------------------------+
$$[/go]
with the same result?

Yes Jann I agree with you, white can claim for a territory in the center. This position looks a seki in J2003 and this seki result seems more in the spirit of japonese rule. Agreed.

Let me try to understand the issue. Objectively white has clearly an advantage : her two groups in the middle have an eye, and, with the white group at the right white can choose between a seki or a disvantage ko. Black as nothing to compensate.
In GT territory rule its sufficient for claiming for a territory in the middle where it is not sufficient in J2003.

What conclusion. Yes OC pass-ko have drawback but may also have some advantage. That's true.
What about your example? Surely such configuration will never happen in practice : seven groups in seki and in addition a special configuration of the eyes and the dame. Does that mean that we do not care what result is given by rule.
No OC the rule should at least be consistent. Here I think it is the case because the rule gives an advantageous result for white and objectively white position is better.

Anyway, congratulation Jann for having found such position. I am well aware that you had to spend some time to reach this result.
BTW I like beast => I like your position.
Thank you for your contribution.

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 Post subject: Re: GT territory rule
Post #71 Posted: Wed Aug 25, 2021 5:24 am 
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RobertJasiek wrote:
Quote:
covered by a "two-eye formation"


Such a rule needs a specification of the player whose two-eye-formation it shall be.

Do you refer to a spefic position I handled?
The player who is claiming for a territory is the player who tries to cover her territory with two-eye formation. Is it unclear?
Does your comment concern the basic ideas behind my proposal or the wording itself?

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 Post subject: Re: GT territory rule
Post #72 Posted: Wed Aug 25, 2021 5:46 am 
Judan

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For the rules, the ideas behind the rules are immaterial. The rules themselves must be clear. The wording must clearly express what their meaning shall be. In this case, state the player explicitly, at least as a pronoun referring to him stated at an earlier place in the rules text.

Same for the ko rules: they ought to be clear. They are unclear if I have to consult Cassandra's examples to reverse-engineer a guessed rules meaning.

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 Post subject: Re: GT territory rule
Post #73 Posted: Wed Aug 25, 2021 6:13 am 
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Cassandra wrote:
Nevertheless, just another suggestion for improvement:

A set of locations contains a "territory" for a player if:
1) The inside border contains neither empty locations nor stones of the opponent.
2) The outside border contains neither empty locations nor stones of the player.
3) the set of location can be entirely covered by a "two-eye formation" even if the opponent plays first in an alternation game using normal play and the "permanently prohibited" ko (see here after)


I think I understand Guillaume's point and yours.
Theoritically, in a new rule I can always redefine the word "territory". But at the same time I claimed I try to build a rule as close as possible to traditionnal japonese rule. Because territory is a major item in japonese rules it is not a good idea to change the meaning of this word "territory". Instead I can define OC other words for convenience but, in any case, it would be good idea to then give the definition of the the word "territory" hoping this defintion fits exactly the common understanding of this word.

Because I need to have a wording for what I called "territory" I need to create a new wording. As I mentionned in a previous post I do not like very much the word "area" when it is used alone but associating the word "area" with another word could be a good choice.
Let's try to add the word "controlled":
1) instead of example "player's territory" I could say "player's controlled area" or
2) instead of for example "black request a set of location to be a territoy" I can say "black request she controls this area"
3) instead of saying "to build a two eye formation covering all the territory" I can say "to build a two eye formation covering all the controlled area"
etc.

Let's try with this wording:

A set of locations is a "controlled area" for a player if:
1) The inside border contains neither empty locations nor stones of the opponent.
2) The outside border contains neither empty locations nor stones of the player.
3) the set of locations can be entirely covered by a "two-eye formation" even if the opponent plays first in an alternation game using normal play and the "permanently prohibited" ko (see here after)

A "player's territory" is all the locations which are empty or occupied by an opponent stone, in a "player's controlled area".

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 Post subject: Re: GT territory rule
Post #74 Posted: Wed Aug 25, 2021 6:34 am 
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RobertJasiek wrote:
For the rules, the ideas behind the rules are immaterial. The rules themselves must be clear. The wording must clearly express what their meaning shall be. In this case, state the player explicitly, at least as a pronoun referring to him stated at an earlier place in the rules text.

Same for the ko rules: they ought to be clear. They are unclear if I have to consult Cassandra's examples to reverse-engineer a guessed rules meaning.


I am clearly completly unable to define an immateriel rule.

I tried to begin to read the following one and I gave up very very quickly. ;-) ;-) ;-)
OC wording has to be carefully chosen but do not ask me to write an immaterial rule.
I am quite sure at least 99% of professionnal Go players are unable to read the rule here under. Show such rule to a beginner and you will be sure this potential player will choose another game!
Who amongs the readers of this forum is able to read and UNDERSTAND (!) such rule?

Logical Japanese Rules of Go
(precise version)

A. Game

A1. "Two players play an even game of go on some board according to
Logical Japanese Rules of Go "
by doing - essentially - the following in the given order:
1. Randomly decide which player chooses first and which last.
2. The player choosing first must choose an initial state whose
board is the one in use. This state is called "current state".
3. The player choosing last must choose which player is called
"Black". The other is called "White".
4. While the current state is not final, the player having the
turn in it must replace it with one of its successors.
5. When the current state is final, the player with the higher
score in it wins. If both are equal, it's a "jigo" (tie).

A2. "A state is initial" only if all this holds:
1. Its set of black locations is empty.
2. Its set of white locations is empty.
3. Its set of temporarily marked locations is a subset of its
set of locations. (Includes the case that both are the same.)
4. Its set of permanently marked locations is empty.
5. Its black captive count is a non-negative integer not
greater than the number of members of its set of locations.
6. Its white captive count is 0.
7. Its turn is "black".
8. Its pass count is 0 if its set of temporarily marked
locations is empty, otherwise its pass count is -1.
9. Its history is empty.
(A state's "komi" is its first situation's black captive count
minus its first situation's white captive count, and
a state's "first situation" is the first member of the list
formed by appending its situation to its history.)

A3. "Black has the turn in a state"
only if this state's turn is "black".

A4. "White has the turn in a state"
only if this state's turn is "white".


B. Successor

B1. "State S4 is a successor of state S1"
only if some state S2 and S3 fulfill all this:
1. S1 is not final.
2. a) S1's turn is "black", and
S4 is a white successor of S1; or
b) S1's turn is "white",
S2 is colored reverse to S1,
S3 is a white successor of S2, and
S4 is colored reverse to S3.

B2. "State S4 is a white successor of state S1"
only if some state S2 and S3, text T1 and T2,
integer set K, and integer P fulfill all this:
1. S1's turn is "black".
2. a) S2 is S1, and T1 is "no cycle removed"; or
b) S2 is reachable by removing a cycle in S1,
and T1 is "cycle removed".
3. a) S3 is S2, K is empty, and T2 is "no stone played"; or
b) S3 is reachable by playing a black stone in S2 that
clears set K by ko, and T2 is "stone played".
4. a) T1 is "no cycle removed", T2 is "no stone played",
and P is S1's pass count plus 1; or
b) K is not empty, and P is -1; or
c) K is empty, T1 is "cycle removed" or T2 is "stone played",
and P is 0.
5. S4's history is S1's history with S1's situation appended to it,
S4's set of temporarily marked locations is K,
S4's pass count is P,
S4's turn is "white",
and everything else in S4 is as in S3.

B3. "State S2 is reachable by removing a cycle in state S1"
only if some list of situations H, list of integer sets L,
integer set B and C and D, and integer NB and NW fulfill
all this:
1. S1's pass count isn't 1.
2. H is a trailing sub-list (a suffix) of S1's history,
and H's first member is similar to S1's situation.
(This includes the case that H is S1's history.)
3. L is the list that would result if every member of H
would be replaced by the union of its set of black
locations with its set of white locations.
4. B is the union of all members of L.
5. C is the intersection of all members of L.
6. D is the set of those members of B not member of C.
7. NB is the number of members of the intersection of D
with S1's set of black locations.
8. NW is the number of members of the intersection of D
with S1's set of white locations.
9. S2's black captive count is S1's black captive count plus NB,
S2's white captive count is S1's white captive count plus NW,
S2's set of black locations is the set of those members
of S1's set of black locations not member of D,
S2's set of white locations is the set of those members
of S1's set of white locations not member of D,
S2's set of permanently marked locations is the union
of S1's set of permanently marked locations with D,
and everything else in S2 is as in S1.

B4. "State S3 is reachable by playing a black stone in state S1
that clears integer set K by ko" only if some integer X and
Y and N, state S2, and integer set W fulfill all this:
1. S1's turn is "black".
2. X is member of S1's set of locations, but neither colored
nor marked in S1.
3. S2's set of black locations is S1's set of black locations
extended by X, and everything else in S2 is as in S1.
4. W is the set of all members of S2's set of white locations
that have no liberties in S2.
5. If W is empty, then X has contact to Y in S2 and either
Y is not colored and not permanently marked in S2
or Y is black and permanently marked in S2.
6. N is the number of members of W.
7. S3's set of white locations is the set of those members
of S2's set of white locations not member of W,
S3's white captive count is S2's white captive count plus N,
and everything else in S3 is as in S2.
8. K is W if N is 1 and each neighbor of X in S2 is white in
S2, otherwise K is empty.


C. Score

C1. "Integer N is Black's score in state S1"
only if some integer set L and integer N1 and N2 and N3
fulfill all this:
1. L is the set of those members of S1's set of locations
that Black controls in S1.
2. N1 is the number of members of L that aren't black in S1.
3. N2 is the number of members of L that are white in S1.
4. N3 is S1's white captive count.
5. N is the sum of N1, N2, and N3.

C2. "Integer N is White's score in state S1"
only if some state S2 fulfills all this:
1. S2 is colored reverse to S1.
2. N is Black's score in S2.

C3. "Black controls integer X in state S1"
only if some integer set L fulfills all this:
1. X is member of L.
2. Black can lock L in S1.

C4. "Black can lock integer set L in state S1"
only if some state S2 fulfills all this:
1. L is bordered by Black in S1.
2. S2 is Black's worst case for L in S1.
3. White can't prevent a black 2-eye formation on L in S2.

C5. "Integer set L is bordered by Black in state S1"
only if all this holds:
1. L is a subset of S1's set of locations (this includes the
case that both are the same), and
2. for every member X of L that is neighbor of a Y not member
of L all this holds:
1. X is black in S1, and
2. Y is not black in S1

C6. "State S3 is Black's worst case for integer set L1 in state S1"
only if some integer set L2 and state S2 fulfill all this:
1. S1's set of locations is the union of L1 with L2.
2. S2's history is empty,
S2's set of temporarily marked locations is empty,
S2's black captive count is 0,
S2's white captive count is 0,
S2's pass count is 0,
S2's turn is "white,
S2's set of black locations is the intersection
of S1's set of black locations with L1,
S2's set of white locations is the union
of S1's set of white locations with L2,
S2's set of permanently marked locations is the union
of S1's set of permanently marked locations with L2,
and everything else in S2 is as in S1.
3. S3's set of black locations is the set of those members
of S2's set of black locations that have liberties in S2,
and everything else in S3 is as in S2.

C7. "White can't prevent a black 2-eye formation on integer set L
in state S1" only if at least one holds:
1. Black has build a 2-eye formation on L in S1; or
2. S1's turn is "black",
S1's situation is not final,
S1's situation is not similar to a member of S1's history,
and at least one successor S2 of S1 has the property that
White can't prevent a black 2-eye formation on L in S2; or
3. S1's turn is "white",
S1's situation is not final,
S1's situation is not similar to a member of S1's history,
and each successor S2 of S1 has the property that
White can't prevent a black 2-eye formation on L in S2.

C8. "Black has build a 2-eye formation on integer set L in state S1"
only if all this holds:
1. L is not empty.
2. L shares no member with S1's set of white locations.
3. L is bordered by Black in S1.
4. Every member of L is member of at least one member of
S1's neighbor relation.
5. Every member of S1's neighbor relation that's subset of L
shares at least one member with S1's set of black locations.
6. Every member of L that is colored in S1 has contact to
at least two (different) members of L in S1 which both
are not colored in S1.


D. Contact

D1. "Integer X has liberties in state S1"
only if at least one holds:
1. X is colored and permanently marked in S1. Or
2. X has contact to some Y in S1; and either
a) Y is not colored in S1, or
b) Y has the same color as X in S1 and
Y is permanently marked in S1.

D2. "Integer X has contact to integer Y in state S1"
only if X has contact to Y in state S1 avoiding V,
and V is the set whose only member is X.
("contact" neither is symmetric, reflexive, nor transitive.)

D3. "Integer X has contact to integer Y in state S1 avoiding
integer set V1" only if some integer Z and integer set V2
fulfill at least one:
1. X is neighbor of Y in S1; or
2. Z is neighbor of X in S1,
Z has the same color as X in S1,
Z is not member of V1,
V2 is V1 extended by Z, and
Z has contact to Y in S1 avoiding V2.

D4. "Integer X is neighbor of integer Y in state S1"
only if the set whose only members are X and Y is member
of S1's neighbor relation.
("neighbor" is symmetric, but neither reflexive nor transitive.)

D5. "Integer X is black in state S1"
only if X is member of S1's set of black locations.

D6. "Integer X is white in state S1"
only if X is member of S1's set of white locations.

D7. "Integer X is marked temporarily in state S1"
only if X is member of S1's set of temporarily marked locations.

D8. "Integer X is marked permanently in state S1"
only if X is member of S1's set of permanently marked locations.

D9. "Integer X is colored in state S1" only if at least one holds:
1. X is black in S1, or
2. X is white in S1.

D10."Integer X is marked in state S1" only if at least one holds:
1. X is marked temporarily in S1, or
2. X is marked permanently in S1.

D11."Integer X has the same color as integer Y in state S1"
only if all this holds:
1. X is black in S1 only if Y is black in S1, and
2. X is white in S1 only if Y is white in S1.


E. State

E1. "A state is final" only if its situation is final.

E2. "A situation is final" only if its pass count is 2.

E3. "Two situations are similar" only if either
1. they are the same, or
2. they are not the same, but only differ in their
captive counts.

E4. "State S2 is colored reverse to state S1"
only if some text T fulfills all this:
1. a) T is "black" and S1's turn is "white", or
b) T is "white" and S1's turn is "black".
2. S2's set of black locations is S1's set of white locations,
S2's set of white locations is S1's set of black locations,
S2's black captive count is S1's white captive count,
S2's white captive count is S1's black captive count,
S2's turn is T,
and everything else in S2 is as in S1.

E5. A "state" consists of exactly 3 parts of the given
names and sorts:
1. its "board" - a board
2. its "situation" - a situation
3. its "history" - a list of situations
The first two parts again consist of named parts - subparts of
the state. Since all these subparts have unique names, it's save
to omit the part name when referring to a state's subpart.
(For example, "the state's set of black locations" is short
for "the state's situation's set of black locations".)

E6. A "board" consists of exactly 2 parts of the given
names and sorts:
1. its "set of locations" - a finite integer set
2. its "neighbor relation" - a set of unordered pairs,
where each such pair is a set containing exactly two
(different) members of the board's set of locations

E7. A "situation" consists of exactly 8 parts of the given
names and sorts:
1. its "set of black locations" - an integer set
2. its "set of white locations" - an integer set
3. its "set of temporarily marked locations" - an integer set
4. its "set of permanently marked locations" - an integer set
5. its "black captive count" - a non-negative integer
6. its "white captive count" - a non-negative integer
7. its "turn" - either the text "black" or "white"
8. its "pass count" - either the integer -1, 0, 1, or 2

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 Post subject: Re: GT territory rule
Post #75 Posted: Wed Aug 25, 2021 6:36 am 
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jann wrote:
Your B 1 is bad idea, W then makes bulky five and takes entire board.

As I said, diagram painting helps, doesn't it?

But sadly, most of the contributors here like to solve non-trivial problems in their OWN head only, instead, while very-easy-to-understand examples are covered in extreme detail.

##################################

But nevertheless, amateur's mistakes are nothiiiiiiing that laaaaaaasts foreeeeeeever :D


In the "two-eyed alive" world, different life-and-death status of the components of a "nested" position, which cannot / will not be resolved during "play" seem to be possible in those (very rare) cases, where such position is a compound of at least four (my currect status) groups AND where at least one (even potential) ko-shape is involved. It will play a decicive role (probably amoung others) how "DAME" (e.g. for jann's example) and "loops" (e.g. for positions with multiple ko-shapes) are handled in the ruleset applied.

This is likely to be part of the price that has to be paid for this concept, which is a completely different pair of shoes than the concept of "uncapturable".

--------------------------
--------------------------

Perhaps the following parable will help you understand a bit more what I have in mind with "completely different pairs of shoes".

Commander White:
"Dear Commander Black, your battalion is encircled.
We control every tiny path in this area of battle, so outside help is impossible.
So you should lay down your arms and give up.
Oh yes, before I forget: We are not quite finished with our attack preparations. So please be so kind as not to attempt a breakout until we have fired the first volley from our cannons at you."

Sounds a little nonsense, doesn't it?
But this is exactly, what happens in the "uncapturable" world.

In the world of "two eyes", Black gets the opportunity for attempting an "escape" (which in the case of success will end with a two-eye-formation "inside" White's encirclement that for sure is impossible under "uncapturable").

--------------------------
--------------------------

But HONTE was en route again, so help is on the way for Gérard's proposal :razz:

For resolving jann's seki example successfully (i.e. with the result of "no territory" overall), it will be sufficient (my current status) to exclude "territory" in those monochrome enclosed parts of the board that contain shared liberties of both Black and White stones.
These points would be something like "inside DAME".
Banning opponent's stones inside would be an alternative option.

In the case of GENUINE "two-eye-formations", this will result in no problems, as the opponent's stones are likely to have been taken off the board during status confirmation anyway. Should declaring these stones being "captives" ever have been a dispute.

In the case of GENUINE "seki", this will result in no problems at all from the begining, as both sides will know that nothing could be taken off the board inside, neither during "play" nor during "status confirmation".

In the case of DISPUTED "seki" (e.g. jann's example) it would be too late for White to set her hopes on the result of the status confirmation, as the shared liberties (/ different coloured stones) are determined for the final position of "play". As ususal for a seki, White's groups would be "not dead". Being "two-eyed alive" of "seki alive" (referring to my idea) would make no difference any longer.
A ruleset that had a seperate status for stones that are part of a seki (contrary to Gérard's proposal), would solve jann's example quite easily, as Black's stones in the middle would be "seki-alive", resulting in "territory" being impossible around.

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 Post subject: Re: GT territory rule
Post #76 Posted: Wed Aug 25, 2021 8:38 am 
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Here a new version of "GT territory rule", taking into account the comments already received.
Though I have in my head the concept of "advangeous loop" I think now that I could write the rule without defining explicitly this notion and OC without changing the ideas of the rule I developped in this thread through examples.
My new DRAFT is the following:

Preliminary definitions:
A "two-eye-formation" is a set of one or several strings of the same player and exactly two empty intersections so that each of the strings is adjacent to each of the two intersections, none of the strings is adjacent to another empty intersection, and each of the two intersections is adjacent only to the strings.
The "inside border" of a set of locations is all the locations in the set which are adjacent to a location not in the set
The "outside border" of a set of locations is all the locations outside the set which are adjacent to a location in the set
A set of locations is a "controlled area" for a player if:
1) The inside border contains neither empty locations nor stones of the opponent.
2) The outside border contains neither empty locations nor stones of the player.
3) the set of locations can be entirely covered by a "two-eye formation" through an hypthetical play (see below)
A "player's territory" is all the locations which are empty or occupied by an opponent stone, in a "player's controlled area".

Confirmation phase:
In the confirmation phase any player may claim she "controls an area". This player is called the "attacker" and the other player is called the "defender".
In an hypthetical play the attacker is trying to build a "two-eye formation" covering all the potential "controlled area" while the goal of the defender is the opposite.

Definition:
A position is said to be "critical" if this position is reached by a defender's ko capture followed by an attacker's pass

Hypothetical play
At the beginning of an hypothetical play there are no ko ban
The hypothetical play begins always by a defender move (a play or a pass) and then each player makes moves alternatively.
Normal play is used during hypothetical play except that all the "permanently prohibited kos" created have to be taken into account (the defender is not allowed to capture a ko which have been "permanently prohibited"
Three successive passes ends always an hypothetical play

Procedure to create "permanently prohibited ko":
As soon as a "critical position" is reached the attacker may (it is not mandatory) claim for creating a "permanently prohibited ko":
1) The attacker proves that she can either reach her objective or makes an infinite number of pass
2) The attacker proves that the defender cannot makes an infinite number of pass
3) If the defender agrees to point 1) and 2) then the game continues up to the following "critical position"
4) As soon as a new critical position is reached a "permanently prohibited ko" is automatically created for the ko capture made by the defender before the last pass
5) Then the game continue taking into account the "permanently prohibited ko" created and the attacker may later create another "permanently prohibited ko" using again the procedure above.

Comment 1 : in a critical position it is always the defender to move.
Comment 2 : the points 1) and 2) above ask for an agreement between players. To reach this agreement another board can be used if necessary. If no agreement is possible the referee will have the last word.

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 Post subject: Re: GT territory rule
Post #77 Posted: Wed Aug 25, 2021 10:02 am 
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Gérard TAILLE wrote:
s soon as a "critical position" is reached the attacker may (it is not mandatory) claim for creating a "permanently prohibited ko":
1) The attacker proves that she can either reach her objective or makes an infinite number of pass
2) The attacker proves that the defender cannot makes an infinite number of pass
3) If the defender agrees to point 1) and 2) then the game continues up to the following "critical position"
4) As soon as a new critical position is reached a "permanently prohibited ko" is automatically created for the ko capture made by the defender before the last pass
5) Then the game continue taking into account the "permanently prohibited ko" created and the attacker may later create another "permanently prohibited ko" using again the procedure above.


For a better consistency between points 1) 3) and 4) it seems better to change the wording of point 1) to
1) The attacker proves that she can either reach her objective or reach "critical positions" an infinite number of times

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 Post subject: Re: GT territory rule
Post #78 Posted: Wed Aug 25, 2021 1:49 pm 
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Cassandra wrote:
Excuse me folks, but drawing diagrams would help you a lot, as well as your audience.
I know that this activity can be very painful at times, especially when you have to put the same sequence on paper for the 153rd time.
However, diagram painting enables your audience to easily understand your explanations, as well as the appearance of "Why not here?" moments with yourself.

Click Here To Show Diagram Code
[go]$$B
$$ +---------------------------------+
$$ | O O O O O Y O O T Y T O O X X X |
$$ | O O O O T Y O O O Y O O O X . O |
$$ | O O O O O Y O T O Y O T O X O . |
$$ | O O O O T Y O O O Y O O O X X O |
$$ | O O O O O Y O O O Y O O O X . . |
$$ +---------------------------------+$$[/go]

Let's this be the final position of "play", and White claiming "territory" at any of the triangled points.
=> White claims that she will be able to establish a "two-eye-formation" somewhere on the left part of the board.
=> Black has the right of moving first.




Click Here To Show Diagram Code
[go]$$B :b3: :w4: pass
$$ +---------------------------------+
$$ | O O O O O X O O ? X ? O O X X X |
$$ | O O O O ? X O O O X O O O X ? O |
$$ | O O O O O X O ? O X O ? O X O 2 |
$$ | O O O O ? X O O O X O O O X X O |
$$ | O O O O O X O O O X O O O X X ? |
$$ +---------------------------------+$$[/go]

THE END




Excuse me please, but why white 4 = pass? Why with move four does white not play the bulky 5 atari? Then black must capture, white plays in the middle, and so the black group to the right dies. Where upon white, now kills the rightmost group of five black stones. So THAT claim was correct. However the other group of five black stones remains alic=ve in seki.

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 Post subject: Re: GT territory rule
Post #79 Posted: Wed Aug 25, 2021 2:07 pm 
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Mike Novack wrote:
Excuse me please, but why white 4 = pass?

My mistake has been noticed even earlier => https://lifein19x19.com/viewtopic.php?p=266881#p266881

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 Post subject: Re: GT territory rule
Post #80 Posted: Wed Aug 25, 2021 2:09 pm 
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Mike Novack wrote:
However the other group of five black stones remains alive in seki.

Once White has taken Black's right-hand group off the board, the seki will be resolved completely from right to left.

As I already mentioned earlier several times, painting diagrams would help a lot :D

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