Re: computer-go: Go4++: Passing in tsume searches.

["Michael Reiss" <mick@xxxxxxxxxxxxxxxxx>]

> >So that's two examples found for having to pass twice...
> >anyone construct a 3-pass situation?
> 
> What you are asking for is a seki with mutual liberties.  You can
> construct one with lots of these:
> 
> (lower edge)
> 
>  . . . . . . . . . . . . . . . .
>  . O O O O O O O O O O O O O O .
>  . O X X X X X X X X X X X X O .
>  . O X . . . . . . . . . . X O .
>  . O X O O O O O O O O O O X O .
> 

No because only one defensive pass is actually compulsory. The 
defender can fill all but two of the liberties and then pass.
Then when the attacker passes the situation is deemed seki.

Mick.