You can see here in the corner of the goban a classical tsumego. So the goal of this kind of problem is to see if there is a position for death or live. Here black plays and they are still alive left after the move of the white. The keep on is this one. So if black plays here white plays here and the last move is this one to save the position. So we can see that it’s impossible for the white to take this place or this one so we can have in fact two eyes.