Some remarks on quadratic programming with 0-1 variables

— The aim of this paper is to show that (1) every bivalent (0,1) quadratic programming problem is equivalent to one having a positive f négative) semi-definite matrix in the objective function ; (2) to establish conditions for different classes of local optimality ; (3) to show that any problem of bivalent (0,1) programming is equivalent (a) to the problem of minimizing a real valued function, partly in (0,1 ), and partly in nonnégative variables, (b) to the problem of finding the minimax of a real valued function in bivalent (0,1) variables.