Message #3933

From: Luna Peña <>
Subject: Re: [MC4D] Physical 2x2x2x2 - Canonical moves
Date: Sat, 06 Jan 2018 02:35:14 +0000

I see 5 as the equivalent of doing R L on a 2^3, which is obviously just
two twists. However, it is not as obvious to me how 6 is simple twists.
Perhaps when I get my puzzle and see exactly what it does to the puzzle,
I’ll change my mind, but I would only class moves that are simple on both
the physical and virtual puzzle as primitive.


On 6 Jan 2018 02:32, "Melinda Green [4D_Cubing]" <> wrote:

That’s very helpful, Luna, but I’m curious: Why do you see #5 as primitive
but not #6? Seems to me like it should be both or neither.

On 1/5/2018 6:07 PM, Luna Peña [4D_Cubing] wrote:

OK. Given that, I’d say that:

1-5 are primitive.

7-8 are canonical.

(The rest of ROIL (as in, other twists of the centre 2x2x2 and the
restacked IO twists) may be canonical or may require labeling. I am

6&9(&10?) only with clear labeling (ie. counted as a separate kind of
solve, like macro vs non-macro in MC4D). 11 could possibly be included at a

12 is unacceptable.


On 6 Jan 2018 01:45, "Melinda Green [4D_Cubing]" <> wrote:


#4 is a twist of the central 2x2x2 block about the long axis. It is a twist
of the face joining the two halves of the puzzle. It is equivalent to
twisting both end caps the opposite direction.

#5 is the first "compound move" that I talk about in the video here
<> as a natural
consequence of combining simple rotations with 90 degree twists.

#7 is the fancy 4D change of projection described in the first link in the
description here <>.


On 1/5/2018 9:54 AM, Luna Peña [4D_Cubing] wrote:

Can I get clearer definitions of 4, 5 and 7?


On 4 Jan 2018 23:28, "Melinda Green [4D_Cubing]" <> wrote:

> First off, please check out Zander Bolgar’s lovely solution video
> <> that he invited me to
> share. It’s very cool to see someone developing something like finger
> tricks and blasting through a solution. It’s very much like Bob’s
> <>
> and Joel’s
> <>
> solutions as well as Marc’s <>
> approach.
> This makes for a great launching point for questions about which moves
> should be included in a canonical set. Of course any move that results in a
> reachable state can be justified in a solution, but there’s such a spectrum
> from "obviously fine" to "obviously not". Now that we’ve gotten some
> experience with this puzzle and the practicalities of solving it, I feel
> it’s time to see if we can find some sort of natural canonical set, so I’d
> love to hear your thoughts.
> Here is the list of moves I know about, loosely ordered as described above:
> 1. Simple rotations
> 2. 90 degree twists of outer face
> 3. 180 degree twists of side face
> 4. Center face axial twist
> 5. Arbitrary half-puzzle juxtapositions
> 6. Clamshell move
> 7. Whole-puzzle reorientations
> 8. 90 degree twist of side face (each 2x2x1 square rotate in opposite
> directions)
> 9. Single end cap twist (with parity restrictions?) [fine for
> scrambling]
> 10. Restacking moves [fine for scrambling]
> 11. Single piece flip
> 12. Reassemble entire puzzle
> I suspect the trickiest part has to do with #9 which is the one I would
> most like to nail down.
> I intend to create a follow-up video to talk about all of these and any
> others you can think of. The way you can help is to offer additions and
> corrections to the above list, and especially in suggesting ways to reorder
> it. Then please suggest where you’d draw three lines:
> - Everything above is primitive (Or "basic" or "elementary" as Joel
> calls them)
> - Everything above is canonical. IE always acceptable in solutions
> - Nothing below is acceptable in solutions.
> Thanks all!
> -Melinda