 To begin, it is worth briefly characterizing certain core features of supervenience relations, as they are now standardly understood in metaphysics (see, e.g., the entry on  supervenience).  Supervenience relations are typically understood as relations between pairs of classes of properties. Consider the claim that a certain class of properties—the A-properties—cannot vary without the B-properties also varying. In this claim, we can call the A-properties the supervening properties, and the B-properties the subvening or base properties.