Key points are not available for this paper at this time.
We consider a set of η first order simultaneous differential equations in the dependent variables y 1 , y 2 , …, y n and the independent variable x ⋮ No loss of gernerality results from taking the functions f 1 , f 2 , …, f n to be independent of x , for if this were not so an additional dependent variable y n+1 , anc be introduced which always equals x and thus satisfies the differential equation
J. C. Butcher (Wed,) studied this question.