As I brought up in another thread (Merge concept of Set and View (also include Collection?) - #9 by crystaln), I think the concepts could be Views and Collections.
A View is a saved query, which includes both what is currently a Set AND all the sub-views of sets and collections that are currently called “views”. A View can query anything, including any Collections.
Then when data is shown, it is ALWAYS a View (or “Inline View”, tho this distinction seems unnecessary). A View of everything in a Collection. It could be a View of all Humans (currently a Set). It could be a View of all Tasks assigned to some specific Human ordered by Priority (currently a view of a Set).
In addition to “Set”, this gets rid of the concepts of “Inline Set” and “Inline Collection” - they are all just a View where the source is defined in that view as a collection or query. Many Views of different sources could be shown as tabs on the same UI element.
Views could even have parameters added at a later time, so the specific Human could be passed in, the current user, etc.
Since a Collection doesn’t have to be a query, it’s just a manually created collection of things. It could also be a type of View where the query is “where object is A OR object is B OR …”. it may be a separate concept or just some special View type to simplify things