Aa+Ua = Ab+Ub = F+Y = T+V = {Ga,Gb,Gc,Gd}

Stefan

Legend
Joined
May 7, 2006
Messages
7,286
WCA ID
2003POCH01
YouTube
Visit Channel
As a side product of something, I found out that doing Aa and Ua (or Ua first, or the other combinations in the title) exactly produces the four G perms (which one depends on the AUF between the two perms). And these are all combinations that do this.
 
Last edited:
Man, even when I am sarcastic I don't sound as serious (as this post sounds).
 
I just always thought this was obvious. I always saw G perms as a 3-cycle of corners and a 3-cycle of edges, because all that was solved were the 2 adjacent pieces.

Of course it's obvious that each G can be done as some A and some U. But I don't find it obvious that all four can be done with Aa+Ua alone, without using Ab or Ub. Same for Ab+Ub. And I have no idea how it was obvious to you that F+Y and T+V can do this as well, and that there are no other pairs that do this. Pretty impressive if all this was obvious to you.
 
I think it's only obvious that it can be produced with only Aa+Ua or Ab+Ub, as the edge permutation and corner permutations are completely separate of each other.

And you're right, the other combinations were not obvious to me, but the A+U seemed to be the main point of your post.

Edit: Edge permutation and corner permutation aren't separate of each other. Sorry. What I meant was that 3-cycles of edges and 3-cycles of corners are separate of each other.
 
Last edited:
I don't get it. By looking at the diagrams of the G-perms, anyone can see that they are combinations of various A and U perms.

Did you make this thread simply to say that you are surprised that you didn't notice this before? Or is there something else I am missing?
 
I just always thought this was obvious. I always saw G perms as a 3-cycle of corners and a 3-cycle of edges, because all that was solved were the 2 adjacent pieces.
That's not what the title means.

Get four cubes. On one of them do Aa, followed by Ua. On another do Aa followed by y Ua. On another do Aa followed by y2 Ua. On the last one do Aa followed by y' Ua. You will have all 4 different G perms in front of you.

Same goes with Ab+Ub, F+Y, T+V instead of Aa+Ua.
 
That's not what the title means.

Get four cubes. On one of them do Aa, followed by Ua. On another do Aa followed by y Ua. On another do Aa followed by y2 Ua. On the last one do Aa followed by y' Ua. You will have all 4 different G perms in front of you.

Same goes with Ab+Ub, F+Y, T+V instead of Aa+Ua.
Ah. I see. This makes more sense.
 
So an Aa followed by an Ua (from ANY angle) will always produce one of the Gs? And same goes with the other combos there? Interesting.

EDIT: So the angle that the second algorithm is applied determines which G? And each angle corresponds to a different G? Woah. Makes sense now.
 
Last edited:
I think it's only obvious that it can be produced with only Aa+Ua or Ab+Ub, as the [...] 3-cycles of edges and 3-cycles of corners are separate of each other.

I disagree. Just looking at the PLL diagrams, the Gs look like this:

Ga = Ua + Aa
Gb = Ub + Ab
Gc = Ub + Ab
Gd = Ua + Aa

Two are Aa+Ua, two are Ab+Ub. Not all four Aa+Ua, or all four Ab+Ub.

I always knew about this

Yeah right.
 
So an Aa followed by an Ua (from ANY angle) will always produce one of the Gs?

Yes, but not only that. Also the other direction. Not only is any Aa+Ua some G, but also any G is some Aa+Ua. All four Gs are generated. That's why I wrote "exactly produces the four G perms" and used "= {Ga,Gb,Gc,Gd}" rather than "⊂ {Ga,Gb,Gc,Gd}".
 
Last edited:
I disagree. Just looking at the PLL diagrams, the Gs look like this:

Ga = Ua + Aa
Gb = Ub + Ab
Gc = Ub + Ab
Gd = Ua + Aa

Two are Aa+Ua, two are Ab+Ub. Not all four Aa+Ua, or all four Ab+Ub.
True, but I still think it can be fairly easily implied that if you apply a 3-cycle of edges and then a 3-cycle of corners that it can only produce a G perm, and since each 3-cycle of corners is being applied to a different orientation of edges, (I think) that each PLL essentially has to be a different PLL. Therefore, if it can only produce a G perm, and each of the final cases has to be different, only the 4 G perms could be produced. It's not 100% obvious, but I think it can be somewhat implied (at least with the Us and As).
 
Thom has a nice "Random Cubing Discussion" topic you could have posted this in without having people hatin on you. It probably wouldn't have gotten as much attention though.
 
Back
Top