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\begin{document}
	
	\begin{gather}  
        \begin{split}
|Uy(t)-U{\tilde{y}}(t)|\leq L|y(t)-{\tilde{y}}(t)|\\
                       +\int_{0}^{\gamma_n} {\omega_{1}} (t,s) \left[ |y(s)-{\tilde{y}}(s)|+ \int_{0}^{s} {\overline{\omega}}_1 (t,s,r)|y(r)-{\tilde{y}}(r)|dr \right] ds \notag\\
                       +\int_{\gamma_{n}}^{t} {\omega_1} (t,s) \left[ |y(s)-{\tilde{y}}(s)|+ \int_{0}^{\gamma_{n}} {\overline{\omega}}_1 (t,s,r)|y(r)-{\tilde{y}}(r)| \right. dr \notag\\
                       + \left. \int_{\gamma_{n}}^{s} {\overline{\omega}}_1 (t,s,r)|y(r)-{\tilde{y}}(r)|dr \right] ds\notag\\
         \leq L|y(t)-\tilde{y}(t)|+{\gamma_{n}}({\tilde{\omega}}_{1n}+\gamma_{n} {\overline{\omega}}_{1n} )|y-\tilde{y} |_{\gamma_n}\notag\\
                       +\int_{\gamma_{n}}^{t}{\tilde{\omega}}_{1n}\left[ |y(s)-\tilde{y}(s)|+\gamma_{n}{\overline{\omega}}_{1n} |y-\tilde{y}|_{\gamma_{n}} \notag\\
                       + \left. {\overline{\omega}}_{1n} \int_{\gamma_{n}}^{s}|y(r)-{\tilde{y}} (r)|dr\right] \mathrm{d}s\notag\\
         \leq L|y(t)-\tilde{y}(t)|+{\gamma_{n}}[{\tilde{\omega}}_{1n}+\gamma_{n} {\overline{\omega}}_{1n} +(n-\gamma_{n} ){\tilde{\omega}}_{1n} {\overline{\omega}}_{1n}]|y-\tilde{y}|_{\gamma_{n}}\notag\\
                       +{\tilde{\omega}}_{1n} [1+(n-\gamma_{n} {\overline{\omega}}_{1n}] \int_{\gamma_{n}}^{t} |y(s)-{\tilde{y}}(s)|ds. \label{eq2.7}
     \end{split}
   \end{gather}
	
\end{document}