Re: [KIF] Re: KIF: Re: SUO: RE: SUMO axiomatization
Pat,
Hey, we already agreed to use row variables, no more convincing is
necessary :-)
I don't agree with your general point that we should include all the
features anyone likes. That would result in a bloated product, roughly
analogous to the earliest versions of KIF or say, common LISP, that would
be very difficult to implement.
Adam
At 02:21 PM 1/22/2002 -0600, Pat Hayes wrote:
>>Chris,
>> Ok, maybe I've got it wrong - can you provide an example of a
>> definition that is useful in the context of SUMO, and which is possible
>> with row variables, but not without?
>
>(Sorry this response is delayed, but...) Let me interject with some examples.
>
>1. The definition of lists.
>2. The possibility of defining finiteness of abstract structures.
>3. The ability to state that a recursive definition is restricted to
>finite cases.
>4. The ability to define general second-order relational properties such
>as those of 'predicative' and 'chained' used in my 'time catalog':
>;;predicative-BASIC
>(defrelation predicative (?r) :=
> (forall (?x @l)
> (<=>
> (?r ?x @l)
> (and (?r ?x) (?r @l)))))
>
>;;chained-BASIC
>(defrelation chained (?r) :=
> (forall (?x ?y @l) (<=> (?r ?x ?y @l)
> (and (?r ?x ?y) (?r ?y @l)))))
>
>;;BASIC-syntax
>(predicative predicative chained)
>
>BTW, to address your point in these messages that some of the divergences
>of opinion are simply matters of taste or aesthetics; I would agree, but
>would add that in such a case, since there is no obligation on anyone to
>use a feature that they find ugly, whereas omitting it from the language
>makes it impossible for anyone else to use it, that it is clear that in
>such cases of divergence of opinion, the only reasonable way to proceed is
>to include the feature in the language as an option.
>
>Pat
>
>
>>Adam
>>
>>At 01:57 PM 12/20/2001 -0600, Chris Menzel wrote:
>>>Adam wrote:
>>>> The point about language complexity is not really debatable. I think it
>>>> makes the syntax more complex which I consider simply equivalent to a
>>>> factual statement that it requires more clauses in the BNF grammar. You
>>>> could interpret "more complex" differently. You could say (as Bill and
>>>> Chris have) that "more complex" refers to the axioms that are needed to
>>>> define particular concepts in the ontology. They've shown good
>>>> examples of
>>>> how row variables make for more compact definitions.
>>>
>>>That doesn't put the point strongly enough, Adam. Row variables don't
>>>simply make for more compact definitions. More typically, they make
>>>certain *possible* that are impossible without them. They wouldn't be
>>>terribly interesting if they simply saved a few bytes. Row variables make
>>>KIF strictly more expressive than first-order.
>>>
>>>> Are they simpler or easier to understand? It depends on what community
>>>> you're addressing, and comes down to personal preference, not a statement
>>>> of right or wrong.
>>>
>>>That would be so only if the added mechanisms (as in the case of sorts)
>>>added no expressive power -- and even then it might not be a matter of
>>>preference, as certain constructs might make for better computational
>>>efficiency. Either way, it seems to me the issue isn't personal
>>>preference, but rather whether the constructs in question are useful for
>>>building and/or reasoning upon ontologies.
>>>
>>>-chris
>>>
>>>--
>>>
>>> /\ ASCII ribbon | Chris Menzel -- http://philebus.tamu.edu/~cmenzel
>>> \/ campaign | Philosophy Dept, Texas A&M University
>>> /\ against | College Station, TX 77843-4237
>>>/ \ HTML email | voice: 979.845-5660 fax: 979.845.0458
>>
>>Adam Pease
>>Teknowledge
>>(650) 424-0500 x571
>
>
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Adam Pease
Teknowledge
(650) 424-0500 x571