I need help learning these PLL's: Na, Nb, Aa, Ab, Ra, Rb, Ga, Gb, Gc, and Gd. If anybody could help me, it would be very appreciated!
A perms:
The common Aa and Ab algs are inverses of each other: do one backwards and you get the other. Both of them start with an x rotation (and end with an x' rotation, although this rotation isn't technically necessary). There's always one U turn and one U' turn.
x R' U R' D2 R U' R' D2 R2 x'
x R2 D2 R U R' D2 R U' R' x'
(These are actually commutators – algs that look like X Y X' Y', which are also written as [X, Y]. Ignoring the rotations at the start and end, the first alg can be rewritten as
R' U R' D2 R U' R' D2 R2 = R2 (R U R' D2 R U' R' D2) R2
= R2 [R U R', D2] R2
Try doing R U R' D2 R U' R' D2 on a solved cube a few times and watch how the corner pieces move around. If you understand what's going on, it's easier to remember the algs. At least, that's how I learnt the A perms aeons ago.)
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N perms:
This depends on which algs you're trying to learn, but some of the common sets have Na and Nb algs that are mirrors of each other, e.g.
R F U' R' U R U F' R2 F' R U R U' R' F
L' F' U L U' L' U' F L2 F L' U' L' U L F' (executed as r' D' F r U' R' F' D r2 U r' U' r' F r F')
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G perms:
Again, depending on which algs you're trying to learn, they're probably all mirrors and inverses of each other. There may be a D/D' move at the start or a D move at the end, but it doesn't matter when you do it.
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R perms:
Some of the common algs of Ra and Rb are mirrors of each other. These are the ones I use:
R' U2 R U2 R' F R U R' U' R' F' R2
R U2 R' U2 R B' R' U' R U R B R2
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For all the rest of these that aren't the A perms, you pretty much have to rely on drilling them into your muscle memory. Then again, you presumably have already conquered F perm, J perms, V perm, Y perm, etc. so I don't think you'll have much trouble with these.
