Message #3936

From: Luna Peña <scarecrowfish@gmail.com>
Subject: Re: [MC4D] Physical 2x2x2x2 - Canonical moves
Date: Sat, 06 Jan 2018 02:49:14 +0000

I hadn’t seen that, or at least I forgot about it.
I still think it needs labeling though, because you could just do the 180
twists instead.

This matters, because doing the clamshell would cut down on times, and I
think any sort of shortcut like that should be kept separate. The physical
move count of a speedsolve should equal the virtual twist count of the same
scramble, and a clamshell would be one physical move for three virtual
moves.

The R L moves are ok because you still have to physically do both twists.
It’s essentially a fingertrick.

(I’m thinking more about speedsolving than fewest moves)

~Luna

On 6 Jan 2018 02:43, "Melinda Green melinda@superliminal.com [4D_Cubing]" <
4D_Cubing@yahoogroups.com> wrote:

>
>
> #6 is equivalent to three simple 180 degree twists like I demonstrated
> here <https://www.youtube.com/watch?v=_D4m1Kit3TI&t=1m58s>.
> -Melinda
>
> On 1/5/2018 6:35 PM, Luna Peña scarecrowfish@gmail.com [4D_Cubing] wrote:
>
> 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.
>
> ~Luna
>
> On 6 Jan 2018 02:32, "Melinda Green melinda@superliminal.com [4D_Cubing]"
> <4D_Cubing@yahoogroups.com> 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.
> -Melinda
>
>
> On 1/5/2018 6:07 PM, Luna Peña scarecrowfish@gmail.com [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
> unsure.)
>
> 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
> stretch.
>
> 12 is unacceptable.
>
> ~Luna
>
> On 6 Jan 2018 01:45, "Melinda Green melinda@superliminal.com [4D_Cubing]"
> <4D_Cubing@yahoogroups.com <4D_Cubing@yahoogroups..com>> wrote:
>
>
>
> Certainly.
>
> #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
> <https://www.youtube…com/watch?v=_D4m1Kit3TI&t=1m39s> 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 <https://www.youtube.com/watch?v=d2Fh_1m0UVY>.
>
> -Melinda
>
>
> On 1/5/2018 9:54 AM, Luna Peña scarecrowfish@gmail.com [4D_Cubing] wrote:
>
> Can I get clearer definitions of 4, 5 and 7?
>
> ~Luna
>
> On 4 Jan 2018 23:28, "Melinda Green melinda@superliminal.com [4D_Cubing]"
> <4D_Cubing@yahoogroups.com> wrote:
>
>>
>>
>> First off, please check out Zander Bolgar’s lovely solution video
>> <https://www.youtube..com/watch?v=fYxn4wPe2ZE> 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
>> <https://groups.yahoo.com/neo/groups/4D_Cubing/conversations/topics/3803>
>> and Joel’s
>> <https://groups.yahoo.com/neo/groups/4D_Cubing/conversations/messages/3904>
>> solutions as well as Marc’s <https://www.youtube.com/watch?v=pKHU5sFaGvY>
>> 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
>>
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