Razumikhin-type small-gain theorems for large-scale systems with delays

In this work, small-gain theorems for large-scale time-delay systems are developed using a Razumikhin-type approach, both in terms of ISS and IOS. In the spirit of the Razumikhin theorem, the state variables with delays are treated as disturbances to the system. This approach converts the problem of stability analysis for functional differential equations to the more tractable problem of stability analysis for delay-free systems with disturbances.