jill/src/main/java/io/github/agentsoz/jill/lang/Agent.java
public boolean eval(String query) throws BeliefBaseException {
    boolean result = beliefbase.eval(getId(), query);
    lastresult = (result) ? beliefbase.query(getId(), query) : new HashSet<Belief>();
    return result;
  }
public boolean eval(String query) throws BeliefBaseException {
    boolean result = beliefbase.eval(getId(), query);
    lastresult = (result) ? beliefbase.query(getId(), query) : new HashSet<Belief>();
    return result;
  }
Evaluates the given query against this agent's belief base.

@param query the query to evaluate
@return true if the query returned results, false otherwise
@throws BeliefBaseException if something went wrong