Basic Global Relative Invariants For Nonlinear Differential Equations

Begins by specifying the basic relative invariants for the class $\,\mathcal{C}_{m,2}$ that contains equations like $Q {m} = 0$ in which $Q {m}$ is a quadratic form in $y(z), \, \dots, \, y^{(m)}(z)$ having meromorphic coefficients written symmetrically and the coefficient of $\bigl(y^{(m)}(z) \bigr)^{2}$ is $1$.