Re: asn06 take 2 (Abstract Syntax as a kind of ontology?)

Michael Sintek wrote:
> 
> Dave Reynolds wrote:
>> Sandro Hawke wrote:
>>> Thinking more about the abstract syntax question, I find myself
>>> wondering how an abstract syntax is really different from an ontology.
>>> Is there any practical difference between an ontology of Horn rules and
>>> an abstract syntax for Horn rules?  
>> One possible difference is that in an abstract syntax you can say
>> whether ordering is significant or not.  Sure, as you argue, one benefit
>> is that you can say "ordering is not significant here" but you can also
>> (at least in ASN.1) say "ordering *is* significant here". Or perhaps
>> that is just a feature of ASN.1 rather than of abstract syntax notations
>> in general.
>>
>> However, I think an ontology is closer to want we actually want for RIF
>> and the only places we need to preserve order (e.g. in function/relation
>> arguments) can be handled in an ontology.
>>
>>> If this is true, then OWL is a probably a good way to write down our
>>> abstract syntax for RIF.
>> That's also, sort of, what Michael Sintek was pointing out.
> 
> With the big difference that I did not use OWL, since the open-world
> semantics of OWL can result in unexpected results (like missing parts
> of rules are automatically "inferred").

Understood, that's why I said "sort of".

> What we need is a more or
> less closed-world, database schema like ontology language, so exactly
> what RDFS was originally meant to be but is not any more.

Actually I think that is an issue of processing rather than of modelling.

We can use OWL to model what we say will be true of a rule, e.g. that it 
should have at least 1 consequent.

It's true that if one then applied a generic OWL inference engine to it 
one would infer the presence of a missing consequent rather than detect 
an omission. However, it is perfectly possible to also take the same 
modelling but apply closed world checking to instance data (we have 
tools that do this) and so achieve the desired schema-like behaviour.

In that way one could use asn06 is a convenient syntax, translate to OWL 
to give a formal interchange, use that in closed world checkers for 
validation and get an instance serialization syntax (RDF as you say) for 
free.

Dave


Dave

Received on Tuesday, 21 November 2006 15:32:57 UTC