\[\frac{{\mathrm{d}}^{n}w}{{\mathrm{d}z}^{n}}+f_{n-1}(z)\frac{{\mathrm{d}}^{n-1}%
w}{{\mathrm{d}z}^{n-1}}+f_{n-2}(z)\frac{{\mathrm{d}}^{n-2}w}{{\mathrm{d}z}^{n-%
2}}+\dots+f_{1}(z)\frac{\mathrm{d}w}{\mathrm{d}z}+f_{0}(z)w=0\]