Theorem 2 Let b be a |J|-dimensional vector, then  for all

Suppose that  is defined by  for all then  has the same direction as .

Proof: For every |J|-dimensional vector b,

                 

for all  It follows from Lemma 1 and  that

    

for all .

From Theorem 2Kinoshita and Nakanishi  mention that the pair of evaluation rulesand provides a consistent overall evaluation vector among all alternatives.

 Under the assumption that alternative  has the evaluation vector  of  criteria,we

apprlyto estimating alternative  evaluation vector of criteria from  and then obtain .Hence, can be considered as an inverse function of  in the sense as follows:Theorem3 Let b be a|J|-dimensional vector,then  for all   Suppose that is defined by (1) for all then has the same direction as .

Proof: It follows from definitions of  and  that