Another thought. It would seem to me that under either metric,
the position halfway through ought to be "symmetric". I am not
sure just what "symmetric" means here, and my use of the word
is largely arm waving similar to the use of "symmetric" to
describe local maxima prior to "Symmetry and Local Maxima".
But if such a "symmetric" position could be identified, it should
be quite easy to search from it back to Start or back to Superflip
in a minimal number of moves.

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Robert G. Bryan (Jerry Bryan)                        (304) 293-5192
Associate Director, WVNET                            (304) 293-5540 fax
837 Chestnut Ridge Road                              BRYAN@WVNVM
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