You win:-) Yes, you are right. Keep it that way. Maybe adding these explanations/examples may help others, too... Cheers Ivan On 2010-1-4 17:53 , Andy Seaborne wrote: > > > On 04/01/2010 12:31 PM, Ivan Herman wrote: >> Hi Andy, >>>> - I am not sure what "A path of length zero connects a graph node to >>>> itself." means in terms of a triple pattern... >>> >>> ?x :p* ?y needs a meaning. :p* can appear in more complex paths >>> (rdf:first*/rdf:rest). >>> >>> Working backwards from e.g. ?list rdf:first*/rdf:rest ?elt, ?list >>> rdf:first* ?x would match with ?x equal to whatever ?list is. >>> >> >> Hm. Alternatively, ?x :p* ?y would not match anything with length zero? > > Then ?list rdf:rest* ?elt does not match the beginning cell of a list and > > ?list rdf:rest*/rdf:first ?elt > > (which eventually I will write correctly!) > > does not find the first element of a list without making :p* different > from the :p* in :p*/:q > > It does have a nice effect that > > :C rdfs:subClassOf ?class > > includes :C (as per inference rule that :C rdfs:subClassOf :C). > > An app can write "+" to skip the zero match "+" is '1 or more' where "*" > is 'zero or more' > > Andy > -- Ivan Herman, W3C Semantic Web Activity Lead Home: http://www.w3.org/People/Ivan/ mobile: +31-641044153 PGP Key: http://www.ivan-herman.net/pgpkey.html FOAF : http://www.ivan-herman.net/foaf.rdf vCard : http://www.ivan-herman.net/HermanIvan.vcf
Received on Monday, 4 January 2010 17:55:59 UTC