Step5. Inners at middle layers.

After Step4, one pair of Edges must be free. Use this free site effectively.

ex. Exchange u and d rows. (lr')D2(l'r)

ex. Picking a: lD'l' (corrected 8/24/2002)
     Picking c: r'D'r (corrected 8/24/2002)

ex. (lr')Dl'D2r