Xpath filter on empty association

What i need to do is show in a datagrid the objects that are not linked to an account, however i cannot get the correct xpath syntax. I have tried the follow: [not(RecommendModule.SuggestedMaintenance_Account/Profile.Account)] but this did not work. I basically want to do: RecommendModule.SuggestedMaintenance_Account != empty Which seems not to be possible in Xpath. Could some help? After some research this seems to be the correct format: [not(RecommendModule.SuggestedMaintenance_Account/Profile.Account)] However it still doesn't work.
1 answers

Good suggestion Simon