 This algorithm creates a set  S  of sub-strips.For each sub-strip  s ∈ S we know its lower left corner  s.xposition and  s.yposition, its width  s.width, the horizontal lines parallel to the upper and lower border of the item placed last inside this sub-strip  s.upper and  s.lower, as well as the width of it  s.itemWidth.This algorithm has the following properties