just for reference is the email "aj...@apache.org" always one person or is it used by a number of different editors in the dev group?
On Wed, Mar 13, 2019 at 11:15 AM ajs6f <aj...@apache.org> wrote: > > I'm not at all sure where the idea of a "silent consensus" came from. > Certainly there _is_ interest in SHACL (as there should be), but that's all I > can see. > > ajs6f > > > On Mar 13, 2019, at 7:10 AM, Dave Reynolds <dave.e.reyno...@gmail.com> > > wrote: > > > > Hi Marco, > > > > Not a "consensus" that I'm part of so not something I could comment on. > > > > Dave > > > > On 13/03/2019 10:49, Marco Neumann wrote: > >> correct if me if I am wrong but from my vantage point I seem to notice > >> a silent consensus in the RDF community to go from SPIN rules to SHACL > >> which now comes with its own SHACL rule engine [1]. > >> The new SHACL efforts are mostly guided by TopQuadrant and a change > >> from the initial layered approach to go with SPARQL RDF > >> (SPIN+(SHACL-rules)). So I presume the current game plan is that SHACL > >> will "rule" them all in the end. > >> If so it would be nice to have a feature list for SHACL rules. And > >> does this mean it will be rules without validation and just CONSTRUCT > >> queries or are the rule semantic restrictions build into SHACL? I am > >> sure this will work fine for many use cases we have but since we are > >> starting to blur the lines between rules/reasoner/sparql would be nice > >> to have some general autoritative clarification here. > >> [1] > >> https://github.com/TopQuadrant/shacl/blob/master/src/main/java/org/topbraid/shacl/rules/RuleEngine.java > >> On Wed, Mar 13, 2019 at 10:14 AM Dave Reynolds > >> <dave.e.reyno...@gmail.com> wrote: > >>> > >>> Hi Marco, > >>> > >>> Sorry, I'm not aware of other rule engines having been wired to Jena but > >>> that doesn't mean it hasn't been done. In particular I'm surprised > >>> there's not a drools-for-jena project somewhere. People have certainly > >>> experimented with that, even written papers comparing performance [1], > >>> but I'm not aware of any supported tooling. > >>> > >>> Dave > >>> > >>> [1] https://ieeexplore.ieee.org/document/7516153 > >>> > >>> On 12/03/2019 22:18, Marco Neumann wrote: > >>>> so what's your current recommendation for a superior third party rules > >>>> reasoner that works efficiently with the jena tooling? free & commercial > >>>> option welcome > >>>> > >>>> Marco > >>>> > >>>> > >>>> > >>>> On Mon 14. Jan 2019 at 19:16, Dave Reynolds <dave.e.reyno...@gmail.com> > >>>> wrote: > >>>> > >>>>> Hi Barry, > >>>>> > >>>>> [Agreed that dev is probably the better place to discuss this.] > >>>>> > >>>>> The two engines in jena are indeed loosely styled on RETE and on tabled > >>>>> datalog. However, I wouldn't claim they were particularly complete or > >>>>> good implementations of either. So while looking at some of the source > >>>>> literature that inspired them might be helpful don't expect very much of > >>>>> what's covered in the literature to be present in the code. > >>>>> > >>>>> For RETE then the wikipedia article [1] is a good summary and source of > >>>>> starting references. I had a copy of the original Forgy paper [1](ref > >>>>> 1), among others,when I was doing the work. There has been a *lot* of > >>>>> work on improvements to RETE since the 80s and while there were times > >>>>> when we might have done a new forward engine using more modern > >>>>> techniques it never happened. > >>>>> > >>>>> For the backward engine the approach is a variant of SLG-WAM as used for > >>>>> XSB but highly highly simplified since we can't express general tuples > >>>>> or recursive data structures within jena's triples. A few google > >>>>> searches haven't turned up the exact paper that originally inspired the > >>>>> approach. The closest I've found are [2] and [3], which probably cover > >>>>> the same ground. > >>>>> > >>>>> Let me reinforce that the Jena engines are really simplified. They were > >>>>> enough to get the job done at the time (over a decade ago now) and have > >>>>> proved useful for some people since but I wouldn't want to defend any of > >>>>> the implementation choices. > >>>>> > >>>>> Dave > >>>>> > >>>>> [1] https://en.wikipedia.org/wiki/Rete_algorithm > >>>>> [2] > >>>>> > >>>>> https://pdfs.semanticscholar.org/2078/96964ee85f983cd861a4f8c5dff0bfc9f03e.pdf > >>>>> [3] > >>>>> > >>>>> https://pdfs.semanticscholar.org/6c6d/26e8fe1b755140ffcb57025b021a046b2a3b.pdf > >>>>> > >>>>> On 14/01/2019 16:33, ajs6f wrote: > >>>>>> I have no useful general information about the reasoning framework, but > >>>>> I am copying this over to dev@. Discussions of how to extend Jena > >>>>> definitely have a place there. > >>>>>> > >>>>>> ajs6f > >>>>>> > >>>>>>> On Jan 14, 2019, at 6:40 AM, Nouwt, B. (Barry) > >>>>> <barry.no...@tno.nl.INVALID> wrote: > >>>>>>> > >>>>>>> Hi all, I want to investigate the inner workings of the > >>>>> GenericRuleReasoner (with the purpose of extending it in the future). In > >>>>> Jena's documentation I read: > >>>>>>> > >>>>>>> "Jena includes a general purpose rule-based reasoner which is used to > >>>>> implement both the RDFS and OWL reasoners but is also available for > >>>>> general > >>>>> use. This reasoner supports rule-based inference over RDF graphs and > >>>>> provides forward chaining, backward chaining and a hybrid execution > >>>>> model. > >>>>> To be more exact, there are two internal rule engines one forward > >>>>> chaining > >>>>> RETE engine and one tabled datalog engine - they can be run separately > >>>>> or > >>>>> the forward engine can be used to prime the backward engine which in > >>>>> turn > >>>>> will be used to answer queries." > >>>>>>> source: https://jena.apache.org/documentation/inference/#rules > >>>>>>> > >>>>>>> Apart from Jena's documentation, Jena's mailing lists and its source > >>>>> code, are there any resources that can better help me grasp what is > >>>>> happening inside the generic rule reasoner? For example, the text above > >>>>> mentions the forward chaining RETE engine and the tabled datalog engine, > >>>>> are there any scientific papers that I might read to better understand > >>>>> their inner workings? > >>>>>>> > >>>>>>> Maybe this question is better suited for the d...@jena.apache.org > >>>>> <mailto:d...@jena.apache.org>? > >>>>>>> > >>>>>>> Regards, Barry > >>>>>>> This message may contain information that is not intended for you. If > >>>>> you are not the addressee or if this message was sent to you by mistake, > >>>>> you are requested to inform the sender and delete the message. TNO > >>>>> accepts > >>>>> no liability for the content of this e-mail, for the manner in which you > >>>>> use it and for damage of any kind resulting from the risks inherent to > >>>>> the > >>>>> electronic transmission of messages. > >>>>>> > >>>>> > >> -- > >> --- > >> Marco Neumann > >> KONA > -- --- Marco Neumann KONA
