Exhibit 3

Proof That X2M Avoids Row Preference
Reversals (RPRs) for Strong Form Row Dominance

 

I. Definitions

(1) X2M Model: Minimize X2 = åi åj ( ( rij - yi / yj ) 2 / ( yi / yj ) ) = åi åj ( rij - yij ) 2 yji
    Subject to:
   

1 = åiyi
0 < yi for i = 1,...,n

(2) X2ij = ( rij - yij ) 2 yji + ( rji - yji ) 2 yij + åk ¹ i, j ( ( rik - yik ) 2 yki + ( rjk - yjk ) 2 ykj + ( rki - yki ) 2 yik + ( rkj - ykj ) 2 yjk )
(3) X2 = X2ij + X-2ij º ( X2 components having a subscript i or j ) + ( All other X2 error components ) for solution vector [ y ] = [ y1,...,yn ]
(4) X2i/j = ( rij - yji ) 2 yij + ( rji - yij ) 2 yji + åk ¹ i, j ( ( rik - yjk ) 2 ykj + ( rjk - yik ) 2 yki + ( rki - ykj ) 2 ykj + ( rkj - yki ) 2 yik
(5) X2/ = X2i/j + X-2ij º ( X2 components having a subscript i or j ) + ( All other X2 error components ) when yi and yj are transposed in [ y ]
(6) DX2ij = X2 - X2/ = X2ij = X2i/j º Change in X2 resulting from transposing yi and yj in [ y ]
.
(7) [ y * ] = [ y1 *,...,yn * ] º Optimal X2M solution vector
(8) yij = yi / yj º X2M model surrogate for the rij response judgment

II. Theorem

If rik > rjk for k = 1,...,n

Then yi * > yj *

Interpretation: If Row i is dominant in the strong form over Row j, then the optimal X2M solution will not reverse the Row i dominance over Row j.

III. Proof

DX2ij = X2ij - X2i/j
  = rij2 ( yji - yij ) + rji2 ( yij - yji ) + åk ¹ i, j ( rik2 ( yki - ykj ) + rjk2 ( ykj - yki ) + rki2 ( yik - yjk ) + rkj2 ( yjk - yik ) )
  = ( rij2 - rj2i ) ( yji - yij ) + åk ¹ i, j ( ( rik2 - rjk2 ) ( yki - ykj ) + ( rkj2 - rki2 ) ( yjk - yik ) )
If yi < yj when rik > rjk for k = 1,...n
Then ( rij2 - rjk2 ) ( yji - yij ) > 0, ( rik2 - rjk2 ) ( ykj - yki ) > 0, and ( rkj2 - rki2 ) ( yjk - yik ) > 0
\ DX2ij = 0 if rik = rjk for all k = 1,...,n
\ DX2ij = 0 if rik > rjk for at least one k among k = 1,...,n

Conclusion: Conditions rij > rjk for all k, rik > rjk for at least one k, and yi < yj Þ yi ¹ yi * and/or yj ¹ yj *. Q.E.D.

IV. Interpretation

In any response matrix [ R ] whose rik elements have a reciprocal property and rik > rjk for all k = 1,...,n, then the optimal X2M solution vector will always have components in which yi * > yj *. In other words, if Row i strongly dominates Row j, then any solution in which yi < yj cannot be X2M optimal since X2 can be reduced simply transposing yi and yj in the solution vector.

Whenever Row i and Row j have identical rik = rjk values for all k = 1,...,n, then no error change can be achieved since DX2ij = 0. However, in this case yi * = yj * in a X2M optimal solution.