Display records not connected

Hello, I need some help with a tricky matter:

I have an Events Object, an EventLog Object and a Members Object.

EventLog is connected to Events Object and to Members Object.

It records the answer of members to a given event (Assist, Maybe, Won't come etc.).
I would like to list the members with no connection to an event, this is the ones who did not answered to an event.

It's easy to list the ones who answered as the aswer creates a record in EventLog with the EventName (connected to Events) and MemberName (connected to Members Object). Members who did not answered do not have a record created in EventLog. Populating all members in EventLog with a "Pending" answer each time I create an event would be a crappy solution (apart the fact I don't know how to do it).

How can I browse/list Members with no connection to the couple (EventName AND MemberName)