this proved interesting. While I don't speak Prolog natively,
   the text was easy enough to read and give metaphors a nice place
   in Logic. I believe metaphors _do_ exist in Logic and that it is
   not devoid of Metaphor, but this here is just the glimmer of the
   idea, from the opposite direction of course, should you have 10
   minutes to glance at a short paper and have an inkling.

   It was a quick google search, and I had to do it, as until you
   mentioned it, I I never considered Logic as being devoid of
   metaphor - in fact, I never knew any aspect of human thought
   that's devoid of metaphor - so the claim is an interesting one.