[ontoiop-forum] OntoIOp teleconference (n.63): Wed 2014.09.10

[Till Mossakowski]

John,

Am 12.09.2014 17:37, schrieb John F Sowa:
> Till,
>
> I have been tied up with too many simultaneous tasks to call in for
> most of the Ontoiop telecons, but I have been following the summaries
> and slides.  Your slides dated 2014-09=09 present a good overview,
> but I had some comments:
>  1. I believe that the discussion can be clarified by using the terms
>     'generalization' and 'specialization'.
>
>  2. Approximation in slide 7 is defined as "model in an expressive
>     language, reason fast in a lightweight one."  That's a good way
>     to make the point.  But it means that the lightweight version
>     is a generalization (is implied by) the more expressive version.
>
agreed. I would call it "logical consequence"...
>  3. Generalization/specialization are the two most widely used
>     metalevel relations among theories.  In Cyc, for example,
>     they are the basis for the partial ordering of microtheories.
>     As another example, Schema.org is a very general (highly
>     underspecified) collection of types (or classes) that many
>     developers have specialized for applications that are
>     inconsistent in the details not specified by Schema.org.
>
so Cyc also uses the terms generalization and specialisation?

>  4. In slide 3, I agree that diversity and interoperability occur at
>     all levels.  But they don't require all systems that interoperate
>     to be consistent with each other in all their details.  If you
>     introduce the term 'generalization', you can say
>
>     a) If two theories A and B are inconsistent in their details,
>        they can interoperate on shared data that is specified by
>        a common generalization C.
>
>     b) To use data specified in C, neither A nor B may assume any
>        properties of that data not specified in C.  But they can use
>        the details in conditionals that begin "If x has property p..."
>
>     c) Points 4a and 4b are implicit in the way interoperable systems
>        work, and the developers who use Schema.org and similar systems
>        can understand them.
>
>  5. Slide 75:  "What is a suitable abstract meta framework for
>     non-monotonic logics and rule languages like RIF and RuleML?"
>
>     There's a lot of research that shows the relationships between
>     nonmon logics and belief (or theory) revision.  In general,
>     every proof in a non-monotonic logic can be converted to a proof
>     in a monotonic logic from a suitably revised theory -- i.e., each
>     nonmon step adds, deletes, or replaces some monotonic axiom.
>     In terms of generalization/specialization, every nonmon proof
>     corresponds to a walk in a lattice of theories.  (The full lattice
>     may be infinite, but there is no need to generate all the nodes.)
Yes, but the important point is that languages like RIF specify in
detail how this walk looks. And then the question is how to abstract
these specifications of such walks to a general notion of nonmonotonic
logic.
>
> I have found that the terms 'generalization' and 'specialization' can
> be explained to a wide audience of developers whose knowledge of logic
> is rudimentary at best.  That's important for the OMG.
>
Best, Till

> John
>
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