- From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
- Date: Mon, 23 Nov 2020 18:59:36 -0500
- To: public-rdf-star@w3.org
Here is a mapping from generalized RDF* to generalized RDF that I believe satisfies all the test cases: Short and a bit sloppy version: Define M on RDF terms as follows: M(I) is the string of I for I an IRI M(L) is the long lexical form of L for L an RDF literal Let L be an injective mapping from RDF triples to "fresh" blank nodes. Define the mapping -* from a generalized RDF* graph G* to a generalized RDF graph G as follows: Pick some embedded triple < s p o > such that none of s, p, and o are embedded triples, replace all occurrences of it by L(< s p o >), and add the triples < L(< s p o >) rdf:type rdf:Statement > < L(< s p o >) rdf:subject s > if s is not a malformed literal < L(< s p o >) rdf:subject* M(s) > if s is not a blank node < L(< s p o >) rdf:predicate p > if p is not a malformed literal < L(< s p o >) rdf:predicate* M(p) > if p is not a blank node < L(< s p o >) rdf:object o > if o is not a malformed literal < L(< s p o >) rdf:object* M(o) > if o is not a blank node Finish when there are no embedded triples left. Longer and more careful version: Let rdf* be an IRI namespace. Let M be an injective mapping from IRIs and RDF literals to strings starting with "X" Let L be an injective mapping from RDF triples to blank nodes whose range excludes an infinite number of blank nodes. Let N be an injective mapping from IRIs to IRIs, strings to strings, and blank nodes to blank nodes that does not include any IRIs in the rdf* namespace or strings that start with "X" or blank nodes in the range of L in its range. (This is just used to ensure that the encoding of IRIs, strings, and blank nodes do not clash with RDF terms in the graphs.) Define the mapping -* from a generalized RDF* graph G* to a generalized RDF graph G as follows: First replace each RDF term by its mapping under N. Pick some embedded triple < s p o > such that none of s, p, and o are embedded triples, replace all occurrences of it by L(< s p o >), and add the triples < L(< s p o >) rdf*:type rdf*:Statement > < L(< s p o >) rdf*:subject s > if s is not a malformed literal < L(< s p o >) rdf*:subject* M(s) > if s is not a blank node < L(< s p o >) rdf*:predicate p > if p is not a malformed literal < L(< s p o >) rdf*:predicate* M(p) > if p is not a blank node < L(< s p o >) rdf*:object o > if o is not a malformed literal < L(< s p o >) rdf*:object* M(o) > if o is not a blank node Finish when there are no embedded triples left. peter On 11/23/20 6:30 AM, Pierre-Antoine Champin wrote: > Hi all, > > as per my action assigned on our last call [1], I pushed a first version of > a test-suite. The first goal is to provide a set of concrete examples of how > RDF* implementations are expected to behave. An HTML rendering of that > test-suite is available here: > > https://w3c.github.io/rdf-star/tests/semantics/manifest.html > > so that everyone can review, reference, and comment each of the test cases. > > If "entail" sounds esoteric to you, think of the 2nd graph in each test case > as a SPARQL* ASK query, which is expected to return TRUE (or FALSE, in the > case of "not entail"). > > Coming next: a similar test suite for SPARQL*. > > best > > [1] https://github.com/w3c/rdf-star/issues/40 > <https://github.com/w3c/rdf-star/issues/40> >
Received on Monday, 23 November 2020 23:59:54 UTC