Hi Drools users, I've got a situation where I've got a list of Drug codes which can only be used for certain prescription codes. The traditional method for implementing this is to simply pre-load the values in a static Hashmap.  Then if get() returns null, it is not a valid combination.  O(1), blazingly fast. The issue with using Drools for this, is that Drools can match a code to a code, and mark it as valid, but cannot call it invalid, as another rule may still be relevant.  Therefore, using Drools for this would require marking combinations as valid, and afterwards, doing a linear traversal of the prescriptions to see if there are any combinations that are not valid. Is this the case?  I would like to try implement it in Drools just for the sake of consistency, but it seems a bit of a hack. Thanks, Daniel -- View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/Using-Drools-as-a-glo... Sent from the Drools - User mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users