Unifying the Tank and Hopfield linear programming circuit and the canonical nonlinear programming circuit of Chua and Lin

The linear programming network of Tank and Hopfield is shown to obey the same unifying stationary cocontent theorem as the canonical nonlinear programming circuit of Chua and Lin. Application of this theorem highlights an error in the design of Tank and Hopfield and suggests how this can be corrected to guarantee the existence of a bounded solution. The accuracy of the solution is maximized when the circuit of Tank and Hopfield reduces to the simplest special case of the canonical nonlinear programming circuit.