I'm trying to understand what you're looking for. Found this (which I am sure you are more advanced than; it's really more for people trying to answer you): http://www.linkeddatatools.com/introducing-rdfs-owl
I think you are looking at a data problem, a kind of logic problem.
E. g. Individual #1 is in A, B, C classes.
Individual #2 is in A, E, and F classes.
Individual #3 is in G class only.
So (if I am understanding your question correctly), you are looking for E and F when it comes to Individual #1, because those are consistent with A even though you don't start off knowing Individual #1 could be consistent with either. Does that make sense? It's a kind of a many to many data relationship, and those are rather difficult to deal with.