anchor.diff:            (bottom (SFBool bottom))
             (top (SFBool top))
             (solid (SFBool solid)))
  +        (gl:with-pushed-matrix
         (gl:rotate -90 1 0 0)
         (gl:translate 0 0 (- (/ height 2)))
  -      (glut:solid-cylinder radius height 20 1))))
  +      (glut:solid-cylinder radius height 20 1)))))
   
   
   ;; ......................................................................Sphere
  
positive.code:   ""
    (format t "Shape~%")
    (with-slots (containerField) self
      (dolist (element containerField)
        (run element))))
  
  ;; ------------------------------------------------------------------appearance
  (defmethod run ((self appearance))
  
negative.code:           (side (SFBool side))
            (bottom (SFBool bottom))
            (solid (SFBool solid)))
        (gl:with-pushed-matrix
        (gl:rotate -90 1 0 0)
        (gl:translate 0 0 (- (/ height 2)))
        (if solid       
            (glut:solid-cone bottomRadius height 20 1)                   ; shape
            (glut:wire-cone bottomRadius height 20 1))))))
  
  ;; ....................................................................Cylinder
  (defmethod run ((self Cylinder))
  