ReactionLinks are often drawn complicated on the diagram.
In order to obtain the clear visual diagram without confusing the intersections, all the ReactionLinks are drawn with the white margins around the lines.
When the ReactionLinks in the figure look complicated, as been piled up to the top from the bottom, the piled order indicates the order of the creation of the ReactionLink.
i.e. newly drawn ReactionLink will be drawn on top of the older links.
To tidy up the layout of the model, see also "Layout" section.
