that is

Use each ordered pair in R to find orthogonality with each ordered pair in R (multiplication is required):

& lt 1，2 & gt； * & lt 1，2 & gt； Invincible

& lt 1，2 & gt； *<3 > invincible

& lt 1，2 & gt； * & lt2，3 >= & lt 1，3 & gt；

& lt 1，2 & gt； *<3 > invincible

& lt3，2 >* & lt 1，2 & gt； Invincible

& lt3,2 > * & lt3,2 > can't be confronted.

& lt3，2 >* & lt2，3 >= & lt3，3 & gt；

& lt3,2 > * & lt3,4 > can't be confronted.

& lt2，3 >* & lt 1，2 & gt； Invincible

& lt2，3 >* & lt3，2 >= & lt2，2 & gt；

& lt2,3 > * & lt2,3 > = non-multiplicative

& lt2，3 >* & lt3，4 >= & lt2，4 >

& lt3，4 >* & lt 1，2 & gt； Invincible

& lt3,4 > * & lt3,2 > can't be confronted.

& lt3,4 > * & lt2,3 > can't be confronted.

& lt3,4 > * & lt3,4 > can't be confronted.

Therefore, R2 (squared) = r * r = {