How would you add to the EDB predicates and rules of Section 12.5.2 additional predicates and rules to take into account the fact that if a method call returns an object, then the variable to which...

How would you add to the EDB predicates and rules of Section 12.5.2 additional predicates and rules to take into account the fact that if a method call returns an object, then the variable to which the result of the call is assigned can point to whatever the variable holding the return value can point to?