Commands

• List : this command shows the content of the knowledge base of rules and facts.
• Save expression : add the expression (rule or fact) in the base. If the expression is a fact the forward-chaining mechanism is fired.
• Drop expression : this command deletes the expression of the base (if exists).
• Empty : delete all the rules and facts in the base.
• In expression : find the clauses that unify with the expression in the base.
• Exit : program exit.
• Proof expression : The expression is proved by means of the backward-chaining mechanism.