SUO: RE: A disclaimer about 'new KIF'
John and Pat:
This is just the sort of discussion which I should like to see more of, and
which I consider essential to achieving clarity in a SUO.
However, although I cannot tell with certainly, I think that you may be
discussing at cross purposes, since John refers to some utilization of a
hierarchy of meta-languages, while Pat speaks only of the expressiveness of
'sorted FOL'.
Clarification?
Jay
I don't think either of you mean that defining mathematical terminology is
trivial. For myself, I'd be hard-pressed to say which task is more
difficult.
-----Original Message-----
From: pat hayes [mailto:phayes@ai.uwf.edu]
Sent: Monday, March 12, 2001 8:51 AM
To: standard-upper-ontology@ieee.org
Subject: SUO: A disclaimer about 'new KIF'
As I have referred in a number of messages to the 'new KIF' that is
going to be out soon and have several neat features, I ought to
explain that this is the product of an ad-hoc group with no
particular official status, and that although we have been in
consultation with Mike Genesereth, the author of the original KIF,
our ideas for a modified version have not yet been approved by him or
indeed by anyone else.
Pat Hayes
PS. That said, I should respond to something thatJohn Sowa said in a
recent message:
The language of core KIF is pure first-order. But we have been
talking about extending KIF to a sorted language, which can be
used as a metalanguage for arbitrary many metalevels. A sorted
first-order language can indeed support true HOL, if you allow
sorts that have uncountably many members.
Actually, sorted FOL/KIF has exactly the same expressive power as
unsorted FOL/KIF, and cannot support true HOL. Also, it seems that
the best way to understand the semantics of KIF (and certainly of the
'new KIF') is that it is in fact a small but significant extension of
pure first-order logic, in that some of its expressions are best
thought of as finite encodings of infinite expressions in the
infinitary logic Lw1w.
John goes on:
But in any case, defining all the terms of mathematics is
almost trivial in comparison to defining all the words of
English. ...
and I entirely agree.
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