As opposed to the graphical interface, textual interface is suitable for most systems, even if they do not have any graphical device or they are too slow to support Tkinter (the graphical widget library for Python). The default textual interface is shown in Figure 6.3. The state of the model is printed before the prompt. Similar to the graphical interface, the user is allowed to enter event names and the ``debug'' and ``exit'' special events. The DUMP macro prints messages to the console.