Complex sentence: An example of the horizon effect occurs when some negative event is inevitable but postponable, but because only a partial game tree has been analysed, it will appear to the system that the event can be avoided when in fact this is not the case.
Split into simpler sentences: An example of the horizon effect occurs when some negative event is inevitable, but postponable. Because only a partial game tree has been analyzed, it will appear that the event can be avoided when in fact this is not the case.