[rules-users] newbie question on "when" condition syntax

Hi, say I have a class with two fields, x and y: public class Test { int x = 1; int y = 2; getters/setters... } I would like a rule which fires when y = x + 1 my initial thought would be something like: rule "Rule 1" when test : Test (y == x + 1) then System.out.println("Rule 1 matches."); end but this is invalid syntax and I can not find any examples of such a rule. I'm doing my best but reading the manual etc. I'm struggling with the syntax here and can't figure it out. any help really appreciated!