RE: rdf as a base for other languages

> From: Sandro Hawke [mailto:sandro@w3.org]
> The "more-complex information" is stored by being described 
> with ground facts.  What's wrong with that?   Where is the confusion?
[...]
> As a specific example, let's imagine a robot which can jump into the
> air.  I can send it knowledge in RDF.  I might say
>   :jump17 a :Jump.
>   :jump17 :height "21cm".
> describing a jump ("jump17") of 21 centimeters.

Things to think about:

1) How would you describe to the robot, in RDF, that it could go anywhere
that was 'safe', and that flat floors were 'safe', stairs were not 'safe',
and the safety status of passing under ladders was unknown?  In particular,
how do you describe the concept of not-safe using ground facts in RDF?

2) How would you extend the RDF describing the above to allow it to be
interrogated by non-robot user agents, such as a suitably enhanced Web
browser?  How would you do this in such a way that the agent did not need
out-of-band knowledge to provide a reasonable presentation of the ground
facts being presented to it in RDF?  In particular, how do you do this
without the user agent requiring an out-of-band definition of not-safe?

		- Peter