- From: Boley, Harold <Harold.Boley@nrc-cnrc.gc.ca>
- Date: Thu, 8 Jan 2004 17:28:02 -0500
- To: 'ntts264' <ntts264@hcmpt.vnn.vn>, www-rdf-rules@w3.org
Hello Sang Thi Thanh Nguyen, > What is the inference in RuleML? > Ex: If "A keeps a book" then "A owns the book". > Is this rule the inference? Well, the earlier RuleML 'own' rule example (http://www.ruleml.org/indtd0.8.html) could now be typed and restricted to books to represent If a person P buys a book B from a merchant M and P keeps B then P owns B as part of the following rulebase: <ruleml:rulebase xmlns:ruleml="http://www.ruleml.org/inspec" xmlns:t="http://ontolib.org#"> <imp> <_body> <and> <atom> <_opr><rel>buy</rel></_opr> <var type="t:Person">P</var> <var type="t:Merchant">M</var> <var type="t:Book">B</var> </atom> <atom> <_opr><rel>keep</rel></_opr> <var type="t:Person">P</var> <var type="t:Book">B</var> </atom> </and> </_body> <_head> <atom> <_opr><rel>own</rel></_opr> <var type="t:Person">P</var> <var type="t:Book">B</var> </atom> </_head> </imp> <fact> <_head> <atom> <_opr><rel>buy</rel></_opr> <ind>Mary</ind> <ind>John</ind> <ind>XMLBible</ind> </atom> </_head> </fact> <fact> <_head> <atom> <_opr><rel>keep</rel></_opr> <ind>Mary</ind> <ind>XMLBible</ind> </atom> </_head> </fact> </ruleml:rulebase> Using this rule, the two facts, and appropriate (OWL/RDFS) types for Mary, John, and XMLBible, the query <ruleml:query xmlns:ruleml="http://www.ruleml.org/inspec" xmlns:t="http://ontolib.org#"> <_body> <atom> <_opr><rel>own</rel></_opr> <ind>Mary</ind> <var type="t:Book">W</var> </atom> </_body> </ruleml:query> would successfully bind W to XMLBible as the result of an inference. Similarly, the query <ruleml:query xmlns:ruleml="http://www.ruleml.org/inspec" xmlns:t="http://ontolib.org#"> <_body> <atom> <_opr><rel>keep</rel></_opr> <ind>Mary</ind> <var type="t:Book">W</var> </atom> </_body> </ruleml:query> would successfully bind W to XMLBible as the result of a direct lookup. The system asking such queries would not need to know which ones are being answered by inference vs. by direct lookup. This will also permit to change the rulebase 'implementation' (e.g. by adding often-used 'own' facts), without changing the query interface. Best, Harold
Received on Thursday, 8 January 2004 17:58:45 UTC