Hi, I finally got around to get my hands dirty. And I run into some problem. The results I'm getting are not the ones I expected to get :-). I have a rule: rule "FC.93" when r1: Record( psc == "101", fundType == "1", $pa1: pa == "7111010", sa matches "F1202[0-9]" ) r2: Record( psc == "101", fundType == "1", pa == $pa1, sa matches "F1202[0-9]" ) then System.out.println( "rule FC.93 has been activated" ); System.out.println( "r1: " + r1 ); System.out.println( "r2: " + r2 ); System.out.println(); end and the following set of facts: 1: new Record("101", "0942", "1", "7111010", "F12020") 2: new Record("101", "0942", "1", "7111010", "F12022") 3: new Record("101", "0942", "1", "7111010", "F12024") 4: new Record("101", "0942", "1", "7111020", "F12020") 5: new Record("101", "0942", "1", "7111020", "F12022") With the rule above I expected to get only tuples 1,2 1,3 2,3 Or the printout: rule FC.93 has been activated r1: pa = 7111010, sa = F12020 r2: pa = 7111010, sa = F12022 rule FC.93 has been activated r1: pa = 7111010, sa = F12020 r2: pa = 7111010, sa = F12024 rule FC.93 has been activated r1: pa = 7111010, sa = F12022 r2: pa = 7111010, sa = F12024 Ie, get only 3 activations of the rule. For some reason I'm getting all possible combinations (or is it permutations?...): rule FC.93 has been activated r1: pa = 7111010, sa = F12024 r2: pa = 7111010, sa = F12024 rule FC.93 has been activated r1: pa = 7111010, sa = F12022 r2: pa = 7111010, sa = F12024 rule FC.93 has been activated r1: pa = 7111010, sa = F12024 r2: pa = 7111010, sa = F12022 rule FC.93 has been activated r1: pa = 7111010, sa = F12020 r2: pa = 7111010, sa = F12024 rule FC.93 has been activated r1: pa = 7111010, sa = F12024 r2: pa = 7111010, sa = F12020 rule FC.93 has been activated r1: pa = 7111010, sa = F12022 r2: pa = 7111010, sa = F12022 rule FC.93 has been activated r1: pa = 7111010, sa = F12020 r2: pa = 7111010, sa = F12022 rule FC.93 has been activated r1: pa = 7111010, sa = F12022 r2: pa = 7111010, sa = F12020 rule FC.93 has been activated r1: pa = 7111010, sa = F12020 r2: pa = 7111010, sa = F12020 I recall Edson mentioned that DROOLS would not select the same two facts in the tuple, but that what seems to be happening.... I think I must be doing smth wrong. How the rule should be modified to achieve the result I expect? Also, for some reason regex "F1202\\d" doesn't return any matches as well, while, supposedly the same pattern "F1202[0-9]" does... Thanks. Any hints are very appreciated! Vlad PS: I'm using DROOLS 3.1M on JDK 1.5.0_11 under the 3.1M Eclipse plugin.