This Example , Interior partition Wall Tree shape, shows that how to use output parameter as next input parameter at EKL language. add at List : AddItem (Object: ObjectType, Index: Integer): VoidType add at the end of List Append (Object: ObjectType): VoidType in same time, Randomize modeling method is applied for angles and length. Rand()*length , Rand()*Angle

Thanks to @HC, President at PHI Cubed Inc., &Miami Dade COLLEGE for the collaboration.