5. The system of claim 2 wherein parent-child associations are maintained between graphical symbol templates and graphical symbol instances created from the graphical symbol templates.
5. The system of claim 2 wherein parent-child associations are maintained between graphical symbol templates and graphical symbol instances created from the graphical symbol templates. 6. The system of claim 5 wherein the graphical symbol template design tool includes a template editor for modifying a graphical symbol template stored in the graphical symbol library, and changes by the template editor are propagated, based upon the parent-child associations, to graphical symbol instances created from the changed graphical symbol template.