(rules) should print the rules in the current scope
(ppdefrule friends-rule) should print out the rule named friends-rule
(exit) should exit from zilonis
(clear) Removes all rules and facts from memory. Equivalent to shutting down
and restarting Zilonis (only the current scope).
(reset) Removes facts information from the current scope, and resets the agenda
need to think about this and:
(run) Starts executing a Zilonis program (but not rules) ... think about the
implementation of this....