[next] [prev] [up] Date: Tue, 25 Nov 80 13:08:00 -0500 (EST)
[next] [prev] [up] From: David C. Plummer <DCP@MIT-MC >
~~~ ~~~ [up] Subject: 30 move Plummer Cross algorithm described

Using the {Up Down Left Right Front Back} notation with clockwise
normal and ' (single quote) indicating counter-clockwise:

(B D)^7 that's right, 14 moves. this sets the back face
up and does a couple things to the front.

The next two are general tools to play with three corners
and nothing else, and people should play with them for
their utility.

(L D L') U (L D' L') U'

This fixes front upper left, which leaves front
upper-right, lower-right, lower-left. At this point I
would rotate the entire cube CCW about the front-back
axis so that these become front upper-left, upper-right,
and lower-right, in which case the following transform
becomes (in the new coordinates)
U' (R' D' R) U (R' D R)
but in the old coordinates, we get

R' (D' L' D) R (D' L D)

(+ 14. 8. 8.) ==> 30.

I don't think I made a mistake. Have fun.

IF: Plummer == 2*Christman
THEN Christman=14 (must be even)
and also Plummer=28.

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