I am using Drools 5.2.0 and I encountered the following problem perhaps there is a solution or workaround. I added a new operator called supersetOf which works fine. When I add a rule of the sort: when $myClass: MyClass(X supersetOf $z) then . End It works fine and no errors are displayed in the IDE (eclipse). But when I use nested fields e.g: when $myClass: MyClass(X.Y supersetOf $z) then . End It works fine but I get an error indication by the eclipse marking the drl as a compilation error but looking inside the drl shows no error. Is there any way to resolve this or even workaround by suppressing the error indication? It is quite annoying as my project is filled with false error indication which kind if make it difficult to work. Thanks Hezi