(* Movable Points *)

origin1 = 
    [ x=0, 
      mv_x=@(s)\(dx)s.x:=s.x+dx ];

origin2 = 
    [ x=0, 
      y=0,
      mv_x=@(s)\(dx)s.x:=(s.x+dx), 
      mv_y=@(s)\(dy)s.y:=(s.y+dy) ];

Origin1 = 
    [ new=@(z)[x=@(s)z.x(s), mv_x=@(s)z.mv_x(s)],
      x = \(s)0,
      mv_x = \(s)\(dx)s.x:=s.x+dx ];

Origin2 = 
    [ new=@(z)[x=@(s)z.x(s), y=@(s)z.x(s),
               mv_x=@(s)z.mv_x(s),
               mv_y=@(s)z.mv_y(s)],
      x = Origin1.x,
      y = \(s)0,
      mv_x = Origin1.mv_x,
      mv_y = \(s)\(dy)s.y:=s.y+dy ];