SIMPEN ( body, level, geom, ngeom, ifail )
==========================================

  Simplifies the underlying geometry of a body.

Receives:
  KI_tag_body              *body           --- body to simplify
  KI_cod_slle              *level          --- level of simplification

Returns:
 <KI_tag_list_entity>      *geom           --- list of new geometric entities
 <KI_int_nitems>           *ngeom          --- number of new entities
  KI_cod_error             *ifail          --- failure indicator


Description:
  This function takes a body and attempts to simplify its free form geometry.
  The body itself, and topological nodes in the body are not affected; the
  geometric ones may be replaced by simpler geometries, and the old geometries
  deleted. Tags of all new geometric entities are returned in 'geom'.

  Two levels of simplification are available:

   o SLLEGL - Global simplification

              A B-curve or B-surface will only be replaced if a single
              curve or surface can replace the entire original.

   o SLLELO - Local simplification

              A B-curve or B-surface may be partially replaced by simpler
              curves or surfaces. A side effect of this is that edges or faces
              that were originally on the same B-curve or B-surface, may
              be on different curves or surfaces after the simplification


  The following simplifications may be made on curves:

          original form           simplified form
          -------------           ---------------
             B-curve              line or circle
             B-curve              B-curve with weights removed


  The following simplifications may be made on surfaces

          original form           simplified form
          -------------           ---------------
            B-surface      plane, cylinder, cone, sphere, torus
            B-surface      B-surface with weights removed