Subgradient algorithms for solving variable inequalities
  In this paper we consider the variable inequality problem, that is, to find a solution of the inclusion given by the sum of a function and a point-to-cone application. This problem can be seen as a generalization of the classical system inequality problem taking a variable order structure. Exploiting this special structure, we propose two variants of the subgradient algorithm for solving a system of variable inequalities. The convergence analysis is given under convex-like conditions which, when the point-to-cone application is constant, contains the old subgradient schemes. 
J.Y. Bello Cruz, L.R. Lucambio Perez, G. Bouza Allende
math.OC