COMPOSITIONAL CONTAINMENT HIERARCHY!
A problem I’ve had with sets and “object oriented“ as limited as my understanding is, is the inheritance.
I knew that levels, which are a matter of size usually (scale differences) were a form of hierarchy and yet whenever I’d look deeper into hierarchical stuff, I’d only ever see the kind where all members of a set were basically exchangeable from the perspective of the parent.
So now I found the name of the thing I knew existed but couldn’t find in the literature: it’s called “compositional containment hierarchy”. It is the “other” hierarchy. The one that usually gets written about that I keep finding is known as “Subsumptive containment hierarchy”. That’s the two forms of nested hierarchies.
Good good. Not nuts.