Re: RDF API

Well, if we are talking about the ontology of RDF ...
(I am using the term ontology in the precise sense
defined by Quine, i.e., the set of things which exist).

Nodes exist. In a sense, every node is part of every
chunk of RDF. Its that arcs that may or may not
belong to a chunk of RDF. So, nodes can most
certainly exist independent of arcs. However, arcs
cannot exist independent of nodes. In other words,
you can have something about which you know
nothing, but you cannot know something without
having a thing that knowledge is about.

From that perspective, it makes more sense to
have an algebra of arcs than of nodes.

One need look no farther than predicate logic for
an algebra for RDF. RDF is a very proper subset
of predicate logic.

Guha