Description
Notation3.
N3 is often described as a superset of Turtle, and at the syntactic level it is. At the level that matters here it is something else: N3 adds variables and formulas, and neither exists in RDF's abstract syntax. A formula is a quoted graph -- a term that happens to be a set of statements -- and RDF has no such term.
That is why this is a separate crate rather than more packages inside flyology_rdf. Its model is a strict superset of the RDF one and reuses it wherever the term really is an RDF term, but a consumer that only wants to read Turtle should not be carrying term kinds that RDF cannot express.