[next] [prev] [up] Date: Tue, 06 Jan 81 10:00:00 -0500 (EST)
[next] [prev] [up] From: Don Woods <DON@SU-AI >
~~~ ~~~ [up] Subject: excerpts from Singmaster
[In reply to message from Plummer sent 1 JAN 1981 1315-EST.]

** SPOILER WARNING!! SPOILER WARNING!! **

This message gives the shortest solutions known to Singmaster (as of
the fifth edition of his booklet) for three pretty and moderately
complex patterns, recently referred to as "baseball" (or "worm"),
"snake", and "cube-in-a-cube". People wishing to investigate these
patterns (as described in earlier messages) may not wish to read
further.

Notes: Singmaster uses the half-twist measure. His notation also
includes special representation for the slice (center-twist) and
antislice (such as L+R as opposed to L'+R) operations, which he counts
as two twists; I have expanded this to strict "befuddler" (BFUDLR)
notation in this message.

BASEBALL or WORM

RUFFD'RL'FB'D'F'R'FFRUUFRRF'R'U'F'UUFR

SNAKE

BRL'D'RRDR'LB'RR + UBBU'DBBRLUUR'L'BBD'

It's not too hard to get to the snake, if you don't mind wasting few
twists. Start with DLLRRD' and you're most of the way there. This
assumes you know simple macros for swapping two pairs of edge cubies
and for flipping two edge cubies.

CUBE IN A CUBE

BL'DDLDF'DDFD'B' + F'RUUR'U'BUUB'UF

Again, the cube-in-a-cube is not hard to generate using two instances
of the commutator macro -- R'FRF' UF'U'F U'RUR' -- plus a few simple
extra twists. This is left as an exercise to the reader.

-- Don.

[next] [prev] [up] [top] [help]