L&D problem: can white live without ko?

rlaalswo · #1

White to play first and live. Black has infinte ko threats, so ko is death. Seki and double ko is considered alive.

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

Click Here To Show Diagram Code: [go]$$Bc $$ ------------------ $$ | . . . . O X . . . $$ | . . W . O X . . . $$ | O . . O X X . . . $$ | . . O X X . . . . $$ | O . X X . . . . . $$ | X X X . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

Above is the given solution, but I don't think it's right.

Click Here To Show Diagram Code: [go]$$Bc $$ ------------------ $$ | . 3 . . O X . . . $$ | . . W . O X . . . $$ | O 2 . O X X . . . $$ | . 1 O X X . . . . $$ | O . X X . . . . . $$ | X X X . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

It seems to result in ko or bent four in corner. Am I not right?

EricBackus · #2

rlaalswo wrote:

White to play first and live. Black has infinte ko threats, so ko is death. Seki and double ko is considered alive.

Click Here To Show Diagram Code: [go]$$Bc $$ ------------------ $$ | . 3 . . O X . . . $$ | . . W . O X . . . $$ | O 2 . O X X . . . $$ | . 1 O X X . . . . $$ | O . X X . . . . . $$ | X X X . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

It seems to result in ko or bent four in corner. Am I not right?

I think white lives:

Click Here To Show Diagram Code: [go]$$Bc a and b are miai $$ ------------------ $$ | a 3 4 . O X . . . $$ | . 6 W b O X . . . $$ | O 2 5 O X X . . . $$ | . 1 . X X . . . . $$ | O . X X . . . . . $$ | X X X . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

Click Here To Show Diagram Code: [go]$$Bc $$ ------------------ $$ | . 3 4 . O X . . . $$ | . 5 W . O X . . . $$ | O 2 6 O X X . . . $$ | . 1 O X X . . . . $$ | O . X X . . . . . $$ | X X X . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

jlt · #3

Eric: and if :b5:

is at b?

Cassandra · #4

rlaalswo wrote:

Click Here To Show Diagram Code: [go]$$Bc $$ ------------------ $$ | . 3 . . O X . . . $$ | . . W . O X . . . $$ | O 2 . O X X . . . $$ | . 1 O X X . . . . $$ | O . X X . . . . . $$ | X X X . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

It seems to result in ko or bent four in corner. Am I not right?

Click Here To Show Diagram Code: [go]$$Bc $$ ------------------ $$ | . X . . O X . . . $$ | . 4 O . O X . . . $$ | O O . O X X . . . $$ | . X O X X . . . . $$ | O . X X . . . . . $$ | X X X . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

The status of Bent-Four-in-the-Corner depends on the number of outside liberties!

EricBackus · #5

jlt wrote:

Eric: and if :b5:

is at b?

Uh...ok, nevermind.

rlaalswo · #6

Cassandra wrote:

The status of Bent-Four-in-the-Corner depends on the number of outside liberties!

Click Here To Show Diagram Code: [go]$$Wc $$ ------------------ $$ | 3 X 2 . O X . . . $$ | 4 1 O . O X . . . $$ | O O . O X X . . . $$ | . X O X X . . . . $$ | O . X X . . . . . $$ | X X X . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

Click Here To Show Diagram Code: [go]$$Wc $$ ------------------ $$ | 6 X X 7 O X . . . $$ | X O O 5 O X . . . $$ | O O . O X X . . . $$ | . X O X X . . . . $$ | O . X X . . . . . $$ | X X X . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

Click Here To Show Diagram Code: [go]$$Bc $$ ------------------ $$ | 2 1 4 O O X . . . $$ | 3 O O O O X . . . $$ | O O . O X X . . . $$ | . X O X X . . . . $$ | O . X X . . . . . $$ | X X X . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

Got it! Thanks!