h = .5;  dh = .02;  dw = .1
[
    Ptr: [
        boxht = h; boxwid = dw
     A: box
     B: box
     C: box
        box wid 2*boxwid "..."
     D: box
    ]
  Block: [
        boxht = 2*dw;
        boxwid = 2*dw
        movewid = 2*dh
     A: box; move
     B: box; move
     C: box; move
        box invis "..." wid 2*boxwid; move
     D: box
  ] with .n at Ptr.s - (0,h/2)
  arrow from Ptr.A to Block.A.nw + (dh,0)
  arrow from Ptr.B to Block.B.nw + (dh,0)
  arrow from Ptr.C to Block.C.nw + (dh,0)
  arrow from Ptr.D to Block.D.nw + (dh,0)
]
box dashed ht last [].ht+dw wid last [].wid+dw at last []
