SnotNose: Cut first (). If Black block's White's escape at then White can capture Black's stones at the edge...
SnotNose: Bent 4 corner. White lives by squeeze.
But, as unkx80 said, at kills (easy to verify). So we must try something else with ...
SnotNose: This is only a ko. I think White needs to use the threat/aji of a and b to escape or get more liberties for the stones.