I am having difficulties understanding some lines in the book. "An event can be later than another spacelike separated event in one inertial frame and earlier in another." So for example lets take the thought experiment where lighting strikes two sides of the train, and observers in different frames of reference do not agree which side of the train was stroked first. So events of the lighting strikes are spacelike separated? But it is also written: "Information can be received at P (point) only from events inside or on its past light cone, but not from events outside it." But spacelike separated events do not lie in the light cone. I find somehow contradictory.