Re: soundness and semantics

ewallace@cme.nist.gov wrote:

Thanks, Evans for nicely and accurately rephrasing my thougths.
>> 3. In most cases, the specification of a semantics for interchange
>> purposes is only possible or meanningfull if this specification is
>> simple enough (ie expressible in a few words, not in ten thousand of
>> lines of code) and abstract enough ("abstract" being understood here as
>> "factoring out some aspects").
>> As a consequence, simple and abstract specifications of semantics for
>> RIF rules and rule sets should be a requirement.
>>     
>
> This last bit describes a qualitative aspect of a RIF feature, rather than
> a feature itself.  I am not sure how one can compare abstractness, much
> less understand what "simple enough" or "abstract enough" is.  Thus while
> this seems a good goal, I don't see it as a requirement.  
>   

An interchange format to be used between rule languages L1 and L2 must
have a declarative semantics in which the declarative and the
operational semantics of both L1 and L2 can be mapped (or expressed) into.

This, in my opinion, is should be taken as a requirement.

This is what was meant be the poinrt 3 mewntioned above. An example
might explain it better: the Stable semantics  of non-monotonic
negation  make it possible to express what can be derived/computed from 
a XSB-Prolog rule set without built-ins. In contrast, the semantics of
standard Prolog does not make it possible to declaratively express what
can be derived/computed from  a XSB-Prolog rule set without built-ins
(one can program it in Prolog, but this is not what a RIF streives for.)

François

Received on Thursday, 18 May 2006 07:21:16 UTC