Kill corner?

[Aidoneus]

I did see the tesuji, but I did not see how it would succeed in that case. I was not familiar with this particular life and death problem.

I always tell my math students to not be afraid to ask questions. If one of them needs clarification, there are probably five more students too shy to ask.

So, I am glad if others--including those much stronger than me--benefited from my ignorance!

Edit: For those, like me, without Davies' book, you can find the J group discussed at: http://senseis.xmp.net/?JGroup

[Uberdude]

Ok yeah, it's a J group in the sense of belonging to the J group family of related shapes. My point was the (basic) J group being dead:

$$W
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . O O O . . . . .
$$ | 3 X X X O O . . .
$$ | 4 . . . X 1 . . .
$$ | . 5 . 2 . . . . .
$$ +------------------

Click Here To Show Diagram Code

[go]$$W
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . O O O . . . . .
$$ | 3 X X X O O . . .
$$ | 4 . . . X 1 . . .
$$ | . 5 . 2 . . . . .
$$ +------------------[/go]

doesn't logically imply that this one is:

$$W
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . O O O . . . . .
$$ | 3 X X X O O O . .
$$ | 4 . . . X X O . .
$$ | . 5 . 2 . 1 . . .
$$ +------------------

Click Here To Show Diagram Code

[go]$$W
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . O O O . . . . .
$$ | 3 X X X O O O . .
$$ | 4 . . . X X O . .
$$ | . 5 . 2 . 1 . . .
$$ +------------------[/go]

In this case they are both dead with the same killing sequence, but the tripod group extra leg example shows a shape where this change changes the status. I remember being surprised by this in a game.