1. true - an actor must participate in at least one instance of HasARoleIn, so there can't be an actor who hasn't been in a movie
  2. maybe - there certainly could be actors who have acted in more than 10 movies, but it isn't required so it is also possible there aren't any
  3. maybe - actors are not limited in the number of lead roles they can have, but there's no guarantee that there are any with a leading role in more than one movie
  4. maybe - it is possible, but since leading roles are not required, there may be actors who haven't had one
  5. true - a movie must participate in at least one HasARoleIn instance so there is at least one actor in that movie
  6. maybe - every movie must have at least one and at most two lead actors, so exactly two is possible but not required
  7. maybe - like (b), it is possible for a movie to have more than a dozen actors but it is not required
  8. maybe - every movie must have exactly one director and at least one producer, but they aren't limited to a single producer
  9. maybe - one director and several producers is allowed, so it is possible that some movies fall into that situation
  10. maybe - there is no connection between the actors in a movie and its director, so a director who acts in the same movie is possible
  11. false - a director can direct any number of movies ("false" rather than "maybe" because the statement is about potential - can - rather than actuality in a particular set of entities)
  12. maybe - a director who is an actor-director must have acted in a movie because an instance of AlsoDirects must include an actor who must then participate in an instance of HasARoleIn...but there is no requirement that a director participate in an instance of AlsoDirects
  13. false - there is no connection between the movie involved in Directs and the movie involved in HasARoleIn ("false" rather than "maybe" because the statement is about potential - can - rather than actuality in a particular set of entities)
  14. false - AlsoProduces allows a producer to be an actor (who must then have acted in a movie) ("has ever acted" sounds more like potential, so "false" is a better answer than "maybe")
  15. maybe - the same name could be listed for both producer and director, or there could be an actor-producer-director, but it isn't required that a producer also be a director