Mathematical models and equilibrium in irreversible economic

A system at issue consists of a set of economic agents, an intermediate firm, and an economic reservoir. For this system a set of equilibrium states is considered. Models of irreversible economic are used for description of the system. It is shown for direct purchase process that the state of equilibrium depends on demand functions. If resource exchange process is barter or there exists either currency stock exchange or the economic reservoir or intermediate firm in the system then there is the only equilibrium state.