I have a simple class public class Dummy { private int x1, x2, y1, y2; public Dummy(int x1, int y1, int x2, int y2) { this.x1 = x1; this.y1 = y1; this.x2 = x2; this.y2 = y2; } public int getX1() { return x1; } public int getX2() { return x2; } public int getX2M150() { return x2-150; } public int getY1() { return y1; } public int getY2() { return y2; } } And a the following Rule: rule "DummyRule" ruleflow-group "DummyTest" when d1 : Dummy() d2 : Dummy(y2 == d1.y1, (x1 == (d1.x2 -150) || x2 == (d1.x2 -150))) then System.out.println("Rule DummyTest fired"); end Executing the rule with the following Data - The Rule fires !!! - WRONG Dummy d1 = new Dummy(-1050, -900, -750, -600); Dummy d2 = new Dummy(-1050, -1200, -750, -900); When I modify the Rule the follow way rule "DummyRule" ruleflow-group "DummyTest" when d1 : Dummy() d2 : Dummy(y2 == d1.y1, (x1 == d1.x2M150 || x2 == d1.x2M150)) then System.out.println("Rule DummyTest fired"); end with the same Data - The Rule fires not !!!! - What is CORRECT This problem comes up, when I move from drools 5.01 to 5.3 Can anybody help ? -- View this message in context: http://drools.46999.n3.nabble.com/simple-subtraction-in-drools-5-3-fires-... Sent from the Drools: User forum mailing list archive at Nabble.com.