  A new Small-Gain Theorem is presented for general nonlinear control systems.
The novelty of this research work is that vector Lyapunov functions and
functionals are utilized to derive various input-to-output stability and
input-to-state stability results. It is shown that the proposed approach
recovers several recent results as special instances and is extendible to
several important classes of control systems such as large-scale complex
systems, nonlinear sampled-data systems and nonlinear time-delay systems. An
application to a biochemical circuit model illustrates the generality and power
of the proposed vector small-gain theorem.
