# Rubiks Cube 4x4x4 Top Layer Issue - One Edge Pair Flipped

I have trouble with that edge. Please give algorithm or images for solutions for turning it up so that I can form a cross.

• If you truly want to understand the cube and other permutation puzzles, you need to learn commutators, as explained in this post. Then it is obvious that this is a singe pair swap, which needs a parity fix (e.g. quarter slice turn), after which you have a 5-cycle on the edges and you can also find a 5-cyle on centre-pairs, and each 5-cycle is easily solved using 2 commutators. Of course there are shorter solutions, but they are ad-hoc and require memorization. Nov 3, 2021 at 11:40

The algorithm is

$$r \ U^2$$ - X - $$r \ U^2 \ r\ U^2 \ r' \ U^2\ l \ U^2 \ r' \ U^2\ r \ U^2\ r' \ U^2\ r'$$

Where $$r$$ means you have to turn two layers from the right upwards and $$r'$$ means downwards, $$l$$ means you have to turn two layers from the left downwards. and x means you have to turn the whole cube one face upwards.

Initial

$$rU^2$$

$$\times$$ one face up

$$rU^2$$

$$rU^2$$

$$r'U^2$$

$$lU^2$$ remember left down!

$$r'U^2$$

$$rU^2$$

$$r'U^2$$

$$r'$$

Now you can solve the top layer.