1 Introduction and Problem Formulation
Consider the following nonlinear multi-agent systems consisting of one leader and followers. The dynamics of the leader is described by \begin{equation*} \dot{x}_{0}\ =\ f(t, x_{0}), \tag{1} \end{equation*}
where is the state of the leader, and is continuous and Lipschitz respectively in the first and second argument. The dynamics of the followers is described by \begin{equation*}
\dot{x}_{i} = g_{i}(u_{i}+d_{i}(t))+f(t, x_{i}), i=1, \ldots, N, \tag{2}
\end{equation*}
where and represent the state and control input of the -th follower, respectively; 's are called control coefficients and the sign of 's is called control direction; 's are input disturbances.