On the number of solutions of resistive circuits containing operational amplifiers with saturation

Some conditions are given for a nonlinear equation F(X)+AX=b of a resistive circuit including linear resistors and operational amplifiers with ideal saturation characteristics to have several specific types of solutions. The concern is mainly with solutions lying in the saturation regions of the amplifiers. These solutions can be regarded as equilibrium points, of some dynamical circuits including Hopfield networks.<>