Author summary: ``This paper deals with the stationary states, or operating points, of simple feedback loops consisting of an arbitrary number of nonlinear subsystems. It is assumed that (1) the static input-output relationship of each subsystem is known; (2) little or nothing is known about their dynamics. The analysis results in (a) a graphical construction of the stationary point, or points, of the system, (b) a simple criterion for the asymptotic stability of each stationary point for those feedback loops where each subsystem in the loop has a one-dimensional state space, and (c) a graphical construction for the way in which the operating point is affected by external inputs of the system. A key role in the analysis is played by the (static) open-loop characteristic, a nonlinear analogue of the open-loop gain for linear systems.''