private void	Checks()
  {
    cVertex  v;
    cEdge    e;
    cFace    f;
    int 	   V = 0, E = 0 , F = 0;
    
    Consistency();
    Convexity();
    
    v = list.head;
    if ( v != null )
      do {
	if (v.mark) V++;
	v = v.next;
      } while ( v != list.head );
    
    e = elist.head;
    if ( e != null )
      do {
	E++;
	e = e.next;
      } while ( e != elist.head );
    
    f = flist.head;
    if ( f != null )
      do {
	F++;
	f  = f.next;
      } while ( f  != flist.head );
    CheckEuler( V, E, F );
  }