Rule chaining in Marvel: dynamic binding of parameters

Marvel is a software development environment that uses a rule-based model of the development process. When a user issues a command, Marvel invokes the corresponding rule and binds the rule´s formal parameter to the object selected by the user. If firing the rule changes the object in a way that satisfies the conditions of other rules, Marvel automatically fires each of these rules and tries to bind their formal parameters to objects. Marvel must infer which objects to bind to the formal parameters of the rules in the chain. A problem arises when the classes of the objects manipulated by the rules are different, because Marvel has to determine which object to bind to the parameter of each rule in the chain. Recursive data definitions cause chaining between rules that act on different objects in the same class. Methods developed to address this chaining problem are discussed.<>