## The Professor's Cube

### VII. Solve the Bottom Corners

We have finally reached the bottom layer. While solving the top layer, the user was allowed to solve the corners and edges in any order. While solving the equator, the user was allowed to solve the outer and inner edges in any order. But when solving the bottom layer, that degree of freedom disappears, and the user must follow this particular order:

• Solve the 4 bottom corners FIRST
• Solve the 8 outer-edges NEXT
• Solve the 4 inner-edges NEXT
• Solve center faces LAST

By now, the remaining corners and edges are already at the bottom layer, so there are no more "move-up" or "knock-down" moves anymore. From now on, all moves will either swap pieces around or twist them in their spot. The first step is to arrange the bottom corners in the correct positions:

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## ________________________________

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### Bottom View

You may have to repeat the sequence twice to fix the front bottom corners in place.

### Variations:

For you experts, there are variations to the prior sequence that yield powerful results. There is no need to memorize any of these, as all the other moves give you enough ammunition to solve the cube. But if you want to save a few moves, here they are:

### B- R- B+ L- B- R+ B+ L+ B2

The same 3 corners are swapped counter-clockwise.

### B2 R- B+ L- B- R+ B+ L+

The (bottom) right 2 corner cubes are swapped.

### B+ R- B+ L- B- R+ B+ L+ B+

The (bottom) back 2 corner cubes are swapped.

The two front (bottom corner) cubes should now be in place. The back ones may also be in place; but if they are not, swap them with the following move:

`    `

## B+ R- B+ L- B- R+ B+ L+B+

You only have to do the sequence once to swap the rear bottom corners in place.

All 4 bottom corner cubes are now in place. The next step is to twist each corner so that their bottom sides are the correct color. In the worst-case scenario, NO corner cube has a bottom side with the correct color. In this case, do the following move:

## R- B- R+ B- R- B2 R+ B2

`    `

You only have to do this once. Now there is at least ONE corner cube is finished, with the right color on the bottom side.

Note: Ignore the diagram. As long as you keep the original top face on the top side, this sequence will guarantee that at least ONE bottom-corner cube will be finished afterwards.

Now it is time to finish another corner cube:

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`    `

`    `

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## ________________________

`      `

### Bottom View

You may have to repeat the sequence twice to finish the front bottom corners.

The two front (bottom corner) cubes should now be finished. The back ones may also be done; but if they are not...

`    `

`    `

`    `

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## ________________________________

`      `

### Bottom View

You may have to repeat the sequence twice to finish all four corners.

It is now time to solve the Bottom Outer-Edges.