Life In 19x19

Hmm, so one was able to solve that tsumego? I wonder if it's a misprint. Two more:

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[go]$$c Black must be completely dead, right?
$$ ---------------------------------------
$$ | . O . . O O . . . . . . . . . . . . . |
$$ | . . X O X O . . . . . . . . . . . . . |
$$ | . X X X X O . . . . . . . . . . . . . |
$$ | O O O O O O . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

Click Here To Show Diagram Code

[go]$$c
$$ ---------------------------------------
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | X X . X O . . . . . . . . . . . . . . |
$$ | . . . X O . . . . . . . . . . . . . . |
$$ | O X X O O . . . . , . . . . . , . . . |
$$ | . O O O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

The second one looks soluble, but the best solution I found for B was

jts wrote:Hmm, so one was able to solve that tsumego? I wonder if it's a misprint. Two more:

$$c Black must be completely dead, right?
$$ ---------------------------------------
$$ | . O . . O O . . . . . . . . . . . . . |
$$ | . . X O X O . . . . . . . . . . . . . |
$$ | . X X X X O . . . . . . . . . . . . . |
$$ | O O O O O O . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |

Click Here To Show Diagram Code

[go]$$c Black must be completely dead, right?
$$ ---------------------------------------
$$ | . O . . O O . . . . . . . . . . . . . |
$$ | . . X O X O . . . . . . . . . . . . . |
$$ | . X X X X O . . . . . . . . . . . . . |
$$ | O O O O O O . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

$$c
$$ ---------------------------------------
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | X X . X O . . . . . . . . . . . . . . |
$$ | . . . X O . . . . . . . . . . . . . . |
$$ | O X X O O . . . . , . . . . . , . . . |
$$ | . O O O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |

Click Here To Show Diagram Code

[go]$$c
$$ ---------------------------------------
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | X X . X O . . . . . . . . . . . . . . |
$$ | . . . X O . . . . . . . . . . . . . . |
$$ | O X X O O . . . . , . . . . . , . . . |
$$ | . O O O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

The second one looks soluble, but the best solution I found for B was

... running away:

$$c Seems like there should be a local solution.
$$ ---------------------------------------
$$ | . 6 2 O . . . . . . . . . . . . . . . |
$$ | X X 4 X O . . . . . . . . . . . . . . |
$$ | 3 . 1 X O . . . . . . . . . . . . . . |
$$ | O X X O O . . . . , . . . . . , . . . |
$$ | 5 O O O . . . . . . . . . . . . . . . |
$$ | . 7 . . . . . . . . . . . . . . . . . |

Click Here To Show Diagram Code

[go]$$c Seems like there should be a local solution.
$$ ---------------------------------------
$$ | . 6 2 O . . . . . . . . . . . . . . . |
$$ | X X 4 X O . . . . . . . . . . . . . . |
$$ | 3 . 1 X O . . . . . . . . . . . . . . |
$$ | O X X O O . . . . , . . . . . , . . . |
$$ | 5 O O O . . . . . . . . . . . . . . . |
$$ | . 7 . . . . . . . . . . . . . . . . . |[/go]

I don't know about the first one but here's the second problem:

Ah, ok. I hallucinated a shortage of liberties like so:

HermanHiddema wrote:

$$Bc
$$ ---------------------------------------
$$ | . 6 . 7 . 8 1 . . . . . . . . . . . . |
$$ | 3 O 4 O X X O O 2 . . . . . . . . . . |
$$ | . X 5 X X O X X O . . . . . . . . . . |
$$ | . O X X O O . . O , . . . . . , . . . |
$$ | . O O O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------

Click Here To Show Diagram Code

[go]$$Bc
$$ ---------------------------------------
$$ | . 6 . 7 . 8 1 . . . . . . . . . . . . |
$$ | 3 O 4 O X X O O 2 . . . . . . . . . . |
$$ | . X 5 X X O X X O . . . . . . . . . . |
$$ | . O X X O O . . O , . . . . . , . . . |
$$ | . O O O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

[sl=EternalLife]Eternal Life[/sl]?

I tried to search on google with "eternal live" +"japanese rules". But I only found how the Japanese make eternal love . Though interesting I really wondered what the rules in different versions say about this position if they don't have the super ko rule.
Well, after correcting the spelling of my search, I found some answers in http://senseis.xmp.net/?EternalLife.

edit: herman is right, just click on his link.

@cyclops: did you try clicking the link I made of "Eternal Life" in my post?

Always trying to refute the expert solution I thought I found the refutation.

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[go]$$c
$$ +-----------------------
$$ | . . . . 6 . 1 5 . . .
$$ | . O 2 O X X . . 3 4 .
$$ | 8 X 7 X X O X X O . .
$$ | . O X X O O . . O , .
$$ | . O O O . . . a . . .
$$ | . . . . . . . . . . .[/go]

But, of course, it fails. W's containment is too weak. B easily walks out at a. The problem depends on W being weak around there. Correct?

cyclops wrote:Always trying to refute the expert solution I thought I found the refutation.

$$c
$$ +-----------------------
$$ | . . . . 6 . 1 5 . . .
$$ | . O 2 O X X . . 3 4 .
$$ | 8 X 7 X X O X X O . .
$$ | . O X X O O . . O , .
$$ | . O O O . . . a . . .
$$ | . . . . . . . . . . .

Click Here To Show Diagram Code

[go]$$c
$$ +-----------------------
$$ | . . . . 6 . 1 5 . . .
$$ | . O 2 O X X . . 3 4 .
$$ | 8 X 7 X X O X X O . .
$$ | . O X X O O . . O , .
$$ | . O O O . . . a . . .
$$ | . . . . . . . . . . .[/go]

But, of course, it fails. W's containment is too weak. B easily walks out at a. The problem depends on W being weak around there. Correct?

Yes, I quite like the problem for the fact that it contains such subtle secondary concerns. This one, as well as the double ko death in the corner in entropi's attempt.

Nice sequence cyclops, I would not even consider white giving up those two stones. But if escaping at h15 (or g15) does not lead anywhere (maybe because white is already too strong outside), then black can still play at a18, leading to a 2 step (or 3 step??) ko for life. This time no double-ko, I guess. Or am I again missing something?

entropi wrote:Nice sequence cyclops, I would not even consider white giving up those two stones. But if escaping at h15 (or g15) does not lead anywhere (maybe because white is already too strong outside), then black can still play at a18, leading to a 2 step (or 3 step??) ko for life. This time no double-ko, I guess. Or am I again missing something?

Click Here To Show Diagram Code

[go]$$c
$$ +-----------------------
$$ | . . . . 6 . 1 5 . . .
$$ | 7 O 2 O X X . . 3 4 .
$$ | . X 8 X X O X X O . .
$$ | . O X X O O . . O , O
$$ | . O O O . . . . O . .
$$ | . . . . . O . . . . .[/go]

Thx for the compliment. I wouldn't mind to get some more. But I have no idea where your ko's would arise, b17 seems dead as a stone to me.

cyclops wrote:

entropi wrote:Nice sequence cyclops, I would not even consider white giving up those two stones. But if escaping at h15 (or g15) does not lead anywhere (maybe because white is already too strong outside), then black can still play at a18, leading to a 2 step (or 3 step??) ko for life. This time no double-ko, I guess. Or am I again missing something?

$$c
$$ +-----------------------
$$ | . . . . 6 . 1 5 . . .
$$ | 7 O 2 O X X . . 3 4 .
$$ | . X 8 X X O X X O . .
$$ | . O X X O O . . O , O
$$ | . O O O . . . . O . .
$$ | . . . . . O . . . . .

Click Here To Show Diagram Code

[go]$$c
$$ +-----------------------
$$ | . . . . 6 . 1 5 . . .
$$ | 7 O 2 O X X . . 3 4 .
$$ | . X 8 X X O X X O . .
$$ | . O X X O O . . O , O
$$ | . O O O . . . . O . .
$$ | . . . . . O . . . . .[/go]

Thx for the compliment. I wouldn't mind to get some more. But I have no idea where your ko's would arise, b17 seems dead as a stone to me.

Nowhere, it is dead indeed. I hallucinated a16 would produce a ko, which of course does not. Avoiding such no-brain type obvious mistakes could make me somewhat stronger perhaps...

cyclops wrote:Always trying to refute the expert solution I thought I found the refutation.

$$c
$$ +-----------------------
$$ | . . . . 6 . 1 5 . . .
$$ | . O 2 O X X . . 3 4 .
$$ | 8 X 7 X X O X X O . .
$$ | . O X X O O . . O , .
$$ | . O O O . . . a . . .
$$ | . . . . . . . . . . .

Click Here To Show Diagram Code

[go]$$c
$$ +-----------------------
$$ | . . . . 6 . 1 5 . . .
$$ | . O 2 O X X . . 3 4 .
$$ | 8 X 7 X X O X X O . .
$$ | . O X X O O . . O , .
$$ | . O O O . . . a . . .
$$ | . . . . . . . . . . .[/go]

But, of course, it fails. W's containment is too weak. B easily walks out at a. The problem depends on W being weak around there. Correct?

This is an ancient problem. In ancient problems escape was a factor. Modern compositions tend to be self contained. Different conventions, I suppose, the ancient convention being that the unshown part of the board is empty, the modern convention being that the unshown part of the board is unknown.

Bill Spight wrote:This is an ancient problem.

It can be found in "Shikatsu Myoki".

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[go]$$
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . O . O X X O O . . . . . . . . . . . |
$$ | . X . X X O X X O . . . . . . . . . . |
$$ | . O X X O O . . T , . . . . . , . . . |
$$ | . O O O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

Please take notice that there is no White stone on the marked point.

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[go]$$W White to kill
$$ | . . . . . . . . . . .
$$ | . . . . . . . . . . .
$$ | . W . . . . . . . . .
$$ | . . O O O O O O . , .
$$ | O O X X . X X O . . .
$$ | X X . X . . X O . W .
$$ | X X . . . . . X . . .
$$ ----------------------[/go]

Ah, I see - so that's why modern problems have stones like the marked ones, so you know to focus on the corner?

jts wrote:

$$W White to kill
$$ | . . . . . . . . . . .
$$ | . . . . . . . . . . .
$$ | . W . . . . . . . . .
$$ | . . O O O O O O . , .
$$ | O O X X . X X O . . .
$$ | X X . X . . X O . W .
$$ | X X . . . . . X . . .
$$ ----------------------

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[go]$$W White to kill
$$ | . . . . . . . . . . .
$$ | . . . . . . . . . . .
$$ | . W . . . . . . . . .
$$ | . . O O O O O O . , .
$$ | O O X X . X X O . . .
$$ | X X . X . . X O . W .
$$ | X X . . . . . X . . .
$$ ----------------------[/go]

Ah, I see - so that's why modern problems have stones like the marked ones, so you know to focus on the corner?

heh, I like this problem. I should do more Tsumego.

@jts: That's not a modern problem!

@Marcus: