McMorris, F.R.; Mulder, H.M.; Ortega, O. - Erasmus University Rotterdam, Econometric Institute - 2010
A mean of a sequence Ï€ = (x1, x2, . . . , xk) of elements of a finite metric space (X, d) is an element x for which is … minimum. The function Mean whose domain is the set of all finite sequences on X and is defined by Mean(Ï€) = { x | x is a mean … of Ï€ } is called the mean function on X. In this paper the mean function on finite trees is characterized axiomatically. …