2x2 CLL Pi 4 algorithm

Solve the final four corners of the 2x2 after completing the first layer.

CLL Pi 4 belongs to the Pi group in CLL.

Recognize this starting position

In the inverse-derived training position, the upper-face color points upward at these corner positions: none. Reading each side’s upper corner stickers left to right when facing that side gives F: B U; R: F B; B: U F; L: U U. The letters identify colors by their reference faces.

Execute the algorithm

y2 R' F R F' R U' R' U' R U' R'

The opening is y2 R' F; the final segment is R U' R'. This version contains 11 face, wide, or slice turns and 1 whole-puzzle rotation.