On 12 July 2011 14:40, David Riccitelli <[email protected]> wrote: > I'm configuring the Rules in the seo_rules.sem file for the Refactor engine. > I'm using the attached document as a reference. > > It's not clear to me the difference between the has and values rules. E.g. > in the default seo_rules.sem file I can find both the following rules: > > peopleHomepageRule[is(dbpedia:Person, ?x) . has(foaf:homepage, ?x, ?y) -> > has(google:url, ?x, ?y)] . > organizationHomepageRule[is(dbpedia:Organisation, ?x) . > values(foaf:homepage, ?x, ?y) -> values(google:url, ?x, ?y)] . > > Why in one case has has been used and in the other values? Is there any > practical example about the difference between the two? The main difference is that 'has' keyword applies to relations while 'values' keyword applies to attributes. In the above snippet it is assumed that foaf:homepage can compare as relation between two uris but also as attrbitute with a value of type uri. Since this dual usage of such properties is frequent in linked data, you need to write two rules to catch both, one for each type of range (URI or literal)
Hope this helps Enrico > Thanks, > David > > > -- > David Riccitelli > > Interact SpA > Via A. Bargoni 78 (scala F) > 00153 Roma > > T +39 06 58318 301 > F +39 06 58318 303 > > -- Enrico Daga -- http://www.enridaga.net skype: enri-pan
