I have a question regarding schema equivalence.
In the attached image, I have put two versions of a simple schema.
An actor (with an id and name) can play in more than one play.
A play (with a code and title) can involve multiple actors.
When I write the fact type with a spanning uniqueness constraint in co-referenced form, I get something like the second schema.
Is it necessary to mark the entity type ActorPlaysInPlay is independent? It plays no roles except for those that identify it, but we need to populate this in the database.