[rules-users] recursive queries

Hi all, I am wondering if it is possible to write more complex queries, e.g., running a query inside of a query. An example is that I have one query to enumerate all books, and have another query to enumerate the people that have not read all books. According to a colleague of mine, the syntax for a query only allows the entity LHS in its declaration: http://docs.jboss.org/drools/release/5.2.0.CR1/drools-expert-docs/html/ch... By definition, the entity LHS cannot contain the keyword query, as it can only contain conditional elements: http://docs.jboss.org/drools/release/5.2.0.CR1/drools-expert-docs/html/ch... Any thoughts? Thanks. -Simon