A command is defined as an instantiated LIBLINCKS function that has been executed successfully. The information stored about a command is the function name and wow it was instantiated, i.e. its parameters. Notice that LIBLINCKS always operates on local copies of objects and changes are stored in the common database only with an explicit store operation. We have two different classes of functions (commands) - workspace commands which operate on the local copies of objects and database commands which operate on objects in the actual database.
In the figures, we present the command history as a graph where nodes are commands and arcs indicate temporal succession, see figure 9.
: An example of a command history graph.