Handbook of Research on Emerging Rule-Based Languages and Technologies: Open Solutions and Approaches

Action The general idea of an abstract action is similar to a procedure call in imperative programming languages. The procedures should be defined in 2APL by means of the so-called PC-rules, which stands for procedure call rules (see subsection ‘Procedure Call Rules’ for a description of PC-rules). As we will see in that subsection, a PC-rule can be used to associate a plan to an abstract action. The execution of an abstract action in a plan removes the abstract action from the plan and replaces it with an instantiation of the plan that is associated to the abstract action by a PC-rule. Like a procedure call in imperative programming languages, an abstract action is an expression of the form (i.e. a first order expression in which the predicate starts with a lowercase letter). An abstract action can be used to pass parameters from one plan to another one. In particular, the execution of an abstract action passes parameters from the plan in which it occurs to another plan that is associated to it by a PC-rule. Communication Action A communication action passes a message to another agent. A communication action can have either three or five parameters. In the first case, the communication action is the expression send(Receiver, Performa-