In a contextual ontology (see previous posts) the things that exist relative to an object x do *not* form an equivalence class.
y exists relative to x if y is in immediate physical contact with x.
This solves some problems in the foundations of quantum mechanics. I'll post about it in the next few days.
I'm assuming relational quantum mechanics, where the state of a system is "related to" or "relative to" the reference system. Think Wigner's Friend.