# Message #4072

From: Andy F <legomany3448@gmail.com>

Subject: Re: [MC4D] 2x2x2x2: Monoflip demo side-by-side with MC4D

Date: Thu, 19 Jul 2018 17:43:28 -0400

Thank you; that makes much more sense now. And that algorithm could also be

seen as a conjugate *[IU’ RO2 IF RO2 : IU]* with the first four moves

reorienting pieces to mimic the physical puzzle. Very cool indeed!

- Andy

On Thu, Jul 19, 2018 at 4:22 PM, Marc Ringuette ringuette@solarmirror.com

[4D_Cubing] <4D_Cubing@yahoogroups.com> wrote:

>

>

> Andy,

>

> Oh, now I see what you were saying about the Iy macro’s algorithm looking

> RKT-ish. I think you confused me (and perhaps yourself) by including the

> final IU move in the RKT portion. That final move messes up the "0 mod 4"

> and leaves a twist in the buffer piece. Instead, I’d consider the final

> IU move separately:

>

> Iy (phys) = *IU’ RO2 IF RO2* *IU **RO2 IF’ RO2* IU (virt)

>

> The bold part above corresponds precisely to a nice 3D algorithm on the *I

> *subcube, *F2 U2 R2 F2 z’ y’, *that does not permute any pieces at all,

> but reorients all of them. This is exactly what is needed, since the

> final *IU *is very like the desired *Iy*, permuting the pieces the

> same, except that all the orientations need to end up differently.

>

> Cool.

>

> Cheers

> Marc

>

> On 7/19/2018 10:19 AM, Andy F legomany3448@gmail.com [4D_Cubing] wrote:

>

>

> The *Iy* macro looks like RKT-ified F2 U2 R2 F2 U2 y2 z (equivalent to (F

> B) R2 U2 B2 R2), which is a very bizarre algorithm.

>

>

>

>

–

"Engineers like to solve problems. If there are no problems handily

available, they will create their own problems." - Scott Adams