(defun contact-lens-less ()
  (data
   :name 'contact-lens-less
   :columns '(age perscription astigmatism tear-production lens)
   :egs
   '(
     (YOUNG          MYOPE        YES REDUCED NONE)
     (PRE-PRESBYOPIC MYOPE        YES REDUCED NONE)
     (YOUNG          HYPERMETROPE YES REDUCED NONE)
     (PRE-PRESBYOPIC HYPERMETROPE YES REDUCED NONE)
     (PRE-PRESBYOPIC HYPERMETROPE YES NORMAL  NONE)
     (PRESBYOPIC     MYOPE        YES REDUCED NONE)
     (PRESBYOPIC     HYPERMETROPE YES NORMAL  NONE)
     (PRESBYOPIC     HYPERMETROPE YES REDUCED NONE)
     
     (YOUNG          MYOPE        YES NORMAL  HARD)
     (YOUNG          HYPERMETROPE YES NORMAL  HARD)
     (PRE-PRESBYOPIC MYOPE        YES NORMAL  HARD)
     (PRESBYOPIC     MYOPE        YES NORMAL  HARD)
     
     
     )
     
     ))