d not require that any one definition be used.

&gt; (For example, Cyc doesnt make any firm distinction between a thing 
&gt; and the space it occupies, whereas most mereologies make a very sharp 
&gt; distinction.)
   There may be cases where some choices have to be made in the SUO --
certainly distinguishing between a region of space and the matter
that occupies it is likely to be one of them.  But does CYC really
fail to make any distinction?  That doesn't seem to follow from the 
fragment of CYC availab