illustrating ruler drawing using recursion trace the execution of the recursive draw interval function can be visualized using recursion trace the trace for draw interval is more complicated than in the factorial examplehoweverbecause each instance makes two recursive calls to illustrate thiswe will show the recursion trace in form that is reminiscent of an outline for document see figure output draw interval( draw interval( draw interval( draw interval( draw line( draw interval( draw line( draw interval( draw interval( draw line( draw interval( draw line( draw interval( (previous pattern repeatsfigure partial recursion trace for the call draw interval( the second pattern of calls for draw interval( is not shownbut it is identical to the first