[RDF 1.2 N-Triples] Clarification on tripleTerm production

Hi RDF-star WG,

I have two questions about the current draft of RDF 1.2 N-Triple [1].


As I read it, the draft has two conflicting definitions for how to write
a triple term. Section 2.2 on Triple Terms states:

> A triple term is represented as a tripleTerm with subject, predicate, and
> object preceded by <<, and followed by >>. Note that triple terms may be nested.

The grammar in 5.3, however, produces the triple term as follow:

> tripleTerm  ::=  '<<(' subject predicate object ')>>'

As we can see, the delimiters are '<<(' and ')>>', including parenthesis
in addition to the less-than and greater-than pairs.


Furthermore, the draft contradicts itself in where triple terms may
occur.

While the Abstract states…

> RDF 1.2 N-Triples introduces triple terms as a fourth kind of RDF term which can
> be used as the subject or object of another triple

… throughout the rest of the document, it is assumed that triple terms
may only be the object of a triple.


If I were asked, I'd clarify as follows:

The production rules in the grammar on triple terms should be changed
to only require '<<' and '>>' as delimiters. The additional
parenthesis are not necessary for disambiguation, as the only production
that could collide (IRIREF) does not allow a second less-than character
after its opening delimiter.

As RDF 1.2 Concepts only allow for triple terms in the object position,
the abstract should be corrected to remove the suggestion that triple
terms can be used in the subject position.


Thanks for considering,
Nik

[1] https://www.w3.org/TR/rdf12-n-triples/