Re: computer-go: Live or Die

[Heikki Levanto <heikki@xxxxxx>]

Jeff Massung <jmassung@xxxxxxxxxxxxxxxxx> wrote:

> Okay, I think I might be misunderstanding eyes then.  I thought the 
> definition of an eye, was an enclosed territory where either (a) the enemy 
> cannot enter or (b) it is useless for the enemy to try and enter.

It depends if you are thinking in some formal framework, or just "common
sense". Various formal systems may have their own definitions of eyes (eye
spaces, eye-points, etc).

As you probably know, a group needs two eyes to live. Thus Tim's example 
  x x x x
  x . . x
  x x x x
is sufficient to be one eye, but not enough to live on.

Two such eyes, properly connected, are of course alive
  x x x x . . . . . . x x x x
  x . . x x x x x x x x . . x
  x x x x . . . . . . x x x x

Also, this here counts as two eyes, and is unconditionally alive
  x x x x x x 
  x . . . . x    
  x x x x x x
(if o plays at 1 or 4, x just capures. if 2 or 3, x takes the other middle
point).

I hope this was what you were asking for, and that my explanation clarified
things. If you were after more advanced stuff, ask again, and I see if I
have anything to say about that.

Regards
	Heikki


-- 
Heikki Levanto     LSD Levanto Software Development   heikki@xxxxxxxxxxxxxxxxx
               "In Murphy we Turst"