[Attempto] A Note on Racer

[Adam Wyner]

Hi All,

I'm working with a set of 16 sentences for a policy discussion on
garbage recycling.  I've got them all parsed and nicely semantically
represented with ACE.

Then, I want to test which sets of sentences are consistent, using
RACER.

Some observations.  There are sentences which ACE accepts, but RACER
does not; in particular, RACER reports an error with sentences that
include "should" or "say" -- sentential operators.  This makes sense
since RACER is a first order reasoner, not a modal logical one, which
would be needed for these sorts of constructions.  However, I didn't see
documentation about what RACER can/can't do....  I must be missing an
obvious link.

Also, just a reminder from our early lessons in FOL, just because
something is intuitively inconsistent does *not* mean that it is
logically inconsistent in FOL.  Be attentive to the meanings of the
given logical forms.  For instance, Every man is happy together with No
man is happy is reported as consistent.  But, obviously, this is so
because where there are no men, both are true.  Assert that there is a
man, and the inconsistency is clear.  While this is a simple example,
the same issue might easily arise in more complex knowledge bases and be
hard to root out.

Cheers,
Adam