Figure 6

A computer simulation of the system of Eqs. (4)–(6) with \(c_{1}=0.9~\mathrm{day}^{-1}\), \(c_{2}=0.95~\mathrm{day}^{-1}\), \(c_{3}=0.239~\mathrm{day} ^{-1}\), \(c_{4}=0.91~\mathrm{day}^{-1}\), \(c_{5}=0.49~\mathrm{day}^{-1}\), \(k_{1}=67\), \(k_{2}=0.02\), \(k_{3}=0.9\), \(h_{1}=0.024\), \(h_{2}=0.063\), \(e_{1}=0.00001~\mathrm{day}^{-1}\), \(e_{2}=0.95~\mathrm{day}^{-1}\), \(e_{3}=0.55~\mathrm{day}^{-1}\), \(\gamma _{1}=0.01~\mathrm{day}^{-1}\), \(\gamma _{2}=0.085~\mathrm{day}^{-1}\), \(\epsilon =0.0042\) and \(\delta =0.822\) where \(x(0)=67\), \(y(0)=0.95\) and \(z(0)=0.03\), for which all conditions in Theorem 1 are satisfied. The solution trajectory tends towards a limit cycle as theoretically predicted