From LaSalle
invariance principle [20], we deduce that [Q.sub.0] is globally asymptotically stable.
By LaSalle's
invariance principle [28], we get that [E.sub.f] is globally asymptotically stable when [R.sub.0] [less than or equal to] 1.
Prove Here we use the Lyapunov-LaSalle
invariance principle to prove that [E.sub.0] is overall attracted concerned with [[OMEGA].sub.W [less than or equal to] 1+[epsilon]].
One tool to be used here LaSalle's
invariance principle. If we consider the delay differential system
Equally important in special relativity is the
invariance principle: those different sets of perceptions are the consequence of a common set of physical laws, applicable to all.
It follows from LaSalle
invariance principle [15] that the infection-free equilibrium [E.sup.*.sub.0] is globally asymptotically stable.
In Section 3, by structuring suitable Lyapunov functionals and using LaSalle's
invariance principle we attain the global stability of the uninfected equilibrium if [R.sub.0] [less than or equal to] 1.
Further, by using the well-known Lyapunov-Lasalle
invariance principle, we prove the global asymptotic stability of the infection-free equilibrium, CTL-absent infection equilibrium, and a special case of CTL-present equilibrium.
The convergence analysis is then obtained via an extending LaSalle
invariance principle for impulsive systems in [21].