rpablo007: @Louise Roullier you have forgotten the left side white group. It does only have one eye. So, black could simply capture it,does giving the black's L group additional liberties and the apparently seki becomes a simple capture of the white stones at the right.
Louise Roullier: Hi, I think there is a mistake on Tsumego Dictionary III #858. The solution on the website is this: after the killer nobis from the inside (r17), the defender connects (r16), the killer turns inside (q17), the defender removes a liberty (s16), the killer gives atari to the three stones outside (o19). But, after that, what if the defender simply conects (p18) ? both groups have 2 liberties inside so it's locally seki, except that the defender already has another eye...
Maybe the problem is not "Black/White to kill" but "Black/White to play and get the best result" ?
Thanks for your help! - Louise.
There is a mistake in this problem D3 working