Life In 19x19

I recognize this problem. I remembered seeing it in the Lee Chang Ho Tesuji series. I went and looked through the books to find it and it's on page 237 of book 5. The images in your link are exactly the same as the book.

Here's an interesting tsumego which has recently stumped a good friend on KGS recently. From a somewhat recent Japanese problem book for dans. Enjoy
Black to move

$$Bc
$$ | . . . . . . . . . . .
$$ | . . . . . . . . . . .
$$ | . X X X X X X X . . .
$$ | . X O O . O O X . , .
$$ | . X O . O ...

Wow. I was watching the game on Tygem last night up until move 146 but I went to sleep after that. I knew the game was close after Lee took the ko in the lower left but I thought Gu Li was still going to win.

The closest I can find for black is a direct ko.
#37a Advanced problem
$$Bc
$$-----------
$$|.X753.....
$$|OOOOOX.X..
$$|OXXOXX....
$$|X.XXOO.XX,
$$|6XXOX.OO..
$$|21.O......
$$|4O.O.O....
$$|..........
#37b Intermediate problem
$$Bc 7 at 1
$$-----------
$$|..436OX...
$$|OOO1OOX.X.
$$|.X52.OX ...

handa711 wrote:Nice. Better log in Korea 1 now before it gets full.

Does it usually fill up? I just recently made a Tygem account but I haven't had issues logging onto any of the servers.

@Josh:
To be honest I felt the intermediate one is harder than the advanced :p
The below looks like ko.
$$Bc
$$--------
$$|21OX.X.
$$|OO..OX.
$$|XO.OOX.
$$|.XO,XX.
$$|.XO....
$$|..XX...
$$|.......
Yeah, it's a ko. I don't see anything better at this point though. If there were a black stone at ...

#32a Advanced problem
$$Bc
$$------------
$$|...........
$$|.3.XXXXXO..
$$|.2O.OXOOO..
$$|.1.OOX...,.
$$|..OXXXO....
$$|..OO..O....
$$|.....O.....
$$|...........
$$Bc
$$------------
$$|...........
$$|.53XXXXXO..
$$|.4O.OXOOO..
$$|.12OOX...,.
$$|..OXXXO....
$$|..OO..O....
$$|.....O ...

I haven't found an answer for the advanced problem yet.
#31 a Advanced problem
$$Bc
$$----------
$$|.O.XO....
$$|XXXXXO.O.
$$|OOOOXO...
$$|....XO...
$$|.OOXXO...
$$|.XX..O...
$$|.OOOO....
$$|.........
#31b Intermediate problem
$$Bc
$$-------
$$|..XOO.
$$|OX.XO.
$$|1X.XO.
$$|XX.OO.
$$|OOO ...

Shaddy:

For the sake of discussion.
being w I would try j19. Does it work?
No.
$$Bc
$$-------------
$$|......7.256.
$$|OXXXX.O1.34.
$$|.OOOXO.XXOO.
$$|...,OXXXO,..
$$|...O.OOO.O..
$$|............
$$Bc
$$-------------
$$|.......425..
$$|OXXXX.O1.3..
$$|.OOOXO.XXOO.
$$|...,OXXXO,..
$$|...O.OOO.O ...

For the sake of discussion.
being w I would try j19. Does it work?
No.
$$Bc
$$-------------
$$|......7.256.
$$|OXXXX.O1.34.
$$|.OOOXO.XXOO.
$$|...,OXXXO,..
$$|...O.OOO.O..
$$|............
$$Bc
$$-------------
$$|.......425..
$$|OXXXX.O1.3..
$$|.OOOXO.XXOO.
$$|...,OXXXO,..
$$|...O.OOO.O ...

#29a Advanced problem
$$Bc
$$-------------
$$|............
$$|OXXXXaO.c...
$$|.OOOXObXXOO.
$$|...,OXXXO,..
$$|...O.OOO.O..
$$|............
a and b don't work because of c. Letting white play c seems to mean death, so:
$$Bc
$$-------------
$$|............
$$|OXXXX.O1....
$$|.OOOXO.XXOO ...

Day #28 December 2nd
#28a Advanced problem
$$Bc
$$-----------
$$|..........
$$|.X.O.1.O..
$$|.XO.OOX...
$$|.XXXXXOOO,
$$|.O..OO....
$$|.O.O......
$$|..........
#28b Intermediate problem
$$Bc
$$-----------
$$|...O.O....
$$|XXX.1XXOO.
$$|OOOX.XO...
$$|...O.OO..,
$$|..O.......
$$|..........
#28c ...

Advanced problem:

Well, I'm excited. Hopefully I'll be able to go to the NY/NJ event.