2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/121807The principle of virtual work for dissipative systems is stated. Partially controlled systems are discussed and the concept of a generating families of forms is introduced. The notion of a critical point of a family of convex forms is introduced and discussed. A number of examples is given.16 pagesMathematical Physics70G75, 70C20, 49S05, 52A20text