has been designed in such a way that particle lines may be drawn in relation with one another with a minimum of effort. Instances invariably arise, however, where the simple commands defined thus far become inadequate to the task. The user might then be condemned to perform some algebra or, much worse, to experiment with the positions of lines and vertices in order to make the appropriate lines connect or place labels in the desired positions.
Fortunately a number of features and tricks are available to reduce this unwanted tedium.