where\(X\left(\tau\right)=\ x\left(t\right),\ Y\left(\tau\right)=\ y\left(t\right)\mathcal{,\ M}\left(\tau\right)=\ M(t)\)and \(V_{m}(\tau)\ =\ v_{m}(t).\)
Here \(X\left(.\right),Y\left(.\right)\) And \(\mathcal{M(.)}\) are
the state variables and \(V_{m}(.)\) is the control variable of the
problem (21)-(23). Notice that