jann wrote:
kvasir wrote:
- Click Here To Show Diagram Code
[go]$$B Position 1
$$ | . . . . . . .
$$ | O O . . . . .
$$ | . O . . . . .
$$ | Z O . . . . .
$$ | S X O O O . .
$$ | X X X X O . .
$$ | P X S X O . .
$$ | S O Z O X . .
$$ | O O O O X . .
$$ | . O X X X . .
$$ | O O X . . . .
$$ | X X X . . . .
$$ | . . . . . . .[/go]
I think we may declare this seki in j89 because the marked stones are dead, and the boxes are dame by j89.
I don't see why, B looks outright dead in J89 and all W inside alive thus no dame.
(Maybe you meant the closed pass-for-ko loop? But that would break most examples and we can safely assume is not allowed, the only question is why and how but that seems irrelevant here.)
Maybe I should have qualified the statement better, but Gerard was asking about the confirmation phase with its flaws, and since it was directed at me I wanted to answer with my "understanding" of the j89 semantics (but not to imply that this is really a seki in a game between two people).
Yes, I am assuming black can start taking in the double-ko when white approaches because he asked about the confirmation with its flaws, not how you could fix it.
You said that this does not match many of the examples. This is true. Examples 16-18 seem run afoul of pass-for-ko loops, yet are declared to not be seki. Then examples 19-21 show how the number of liberties do matter when there is a ko.
- Click Here To Show Diagram Code
[go]$$B Example 16
$$ --------------
$$ | . O O . O . O X . X O . O X
$$ | O X X O O O O X X O O O O X
$$ | X X . X X X O X O . O X X X
$$ | . . . . X O X X X O O X
$$ | . . . . X O X . X O X X
$$ | . . . . X O X X O X X
$$ | . . . . X O O O O
$$ | . . . . . . .
$$ | . . . . . . .[/go]
The position is similar to this position which is example 16, and the white stones are declared dead without much detail.
Why is that?
* The example reasons that the seki collapses.
* One could say, like you did, that the double-ko is forbidden but then how and when is it forbidden?
* I tried to think of it as inductive process but there is the problem of allowing what is basically two moves in a row in other positions.