
COMMENTS

r,l,u,d,f,b are respectively right, left, up, down, front, back faces of a 3 X 3 X 3 Rubik's Cube. Set M=2, R=3, L=5, U=7, D=11, F=13, B=17, where M is a 90degree turn of the middle slice of Rubik's Cube; R is a 90degree turn of the right face, L is a 90degree turn of the left face... The moves to permute (ufr,dfr)(ubr,ubl) corners are (R*U)*(R^3*U^3)*(R*U)*(R^3*U^3)*(R*U)*(R^3*U^3) = (3*7)*(3^3*7^3)*(3*7)*(3^3*7^3)*(3*7)*(3^3*7^3) = 21*9261*21*9261*21*9261; note that as the order of a 90degree turn T is 4, then T^2 = T^2 and T^3 = T^1. Moves adapted from 'Adventures in group theory', D. Joyner, J. Hopkins Press.
