The definition of a Bregman function, given by Censor and Lent in 1981 on the basis of Bregman's seminal 1967 paper, was subsequently used in a plethora of research works as a tool for building sequential and inherently parallel feasibility and optimization algorithms. Solodov and Svaiter have recently shown that it is not
Journal of Convex Analysis, Vol. 10 (2003), pp. 245-254.