#Let alpha be a primitive 10th root of unity
#We consider a rational function in 2 variables, of degree 1 in both X and Y.
#Now, it would seem OK to simplify this expression.
#Note that Maple insists on making the denominator have rational coefficients.
#So the numerator and the denominator of this simplified expression are:
#Let's specialise (X,Y) to (alpha^3,0). Note that the original expression is
#defined here. it is not in the conjugate point (alpha,0), though.
#so, num and den are both non-zero in (X,Y)=(x,y).
#num2 and den2 (of the simplified expression) are zero, though.
#so, the quotient can be evaluated with no problem in non-simplified form.
#but in simplified form, maple does not recognise 0/0.