Let us say we have the following ODE: $x^7\frac{d^4y}{dx^4} - y' = 0$
To classify the singular point at $\infty$, we need of course to make a substitution: $x = \frac{1}{t}$, and then evaluate the point $t = 0$. My question is: how can we transform this differential equations in terms on $x$ and $t$? It seems like a very elaborate computational task. Is there an easy way to do this???