Symbolic implementation of preliminary group classiffication for ordinary differential equations

We apply the method of preliminary group classification to ordinary differential equations of the form y(n)=e(x,y,y',.,y(n-1),fi(x)),i=0,.,m. we show how this method can be implemented via the popular symmetry analysis package program lie provided that the package is supplemented with a small file. we then apply this method to an extension of the generalised emden-fowler equation given by y′′ = ∑i=25fixyi. © 2013 k. s. govinder.