Correct!
- You do not need to qualify/identify the ownership or direct participation for any group ( friendlist) as there are exactly the same lists ( or groups) avaiable for every ( and each) user and he/she only participates ( are related) to one ore more groups ( lists) of friendship (the lower associative entity) by a relation of FRIENDSHIP (the entity that implements a self-relationship) So, as you correctly rethought there is no need for the relationship between USER and the FRIENDSHIP_LIST! It would be redundant and even bring problems such this kind of "over-relationship" modeling, because the matter of knowing on which groups are a certain USER is more a matter of processing data ( querying). PS. My only modeling remark point is that the simple 0..N relationship between USER and FRIENDSHIP could be better represented ( as an alternative modeling) by a two simple relationships of USER to show that either the user as the other-user comes from the same entity ( table).