Bug in addition?

[Ilya Zakharevich <ilya@math.ohio-state.edu>]

    ? O(y^5)/(1+x)
	    5
    %3 = O(y )
    ? O(y^5)/(1+x+O(x^6))
	    5       5        5  2      5  3      5  4      5  5     6
    %4 = O(y ) + O(y )x + O(y )x  + O(y )x  + O(y )x  + O(y )x + O(x )
    ? O(y^5)/(1+x)+O(x^6)
	    6
    %5 = O(x )
    ? O(y^6)+O(x^6)
	    6
    %6 = O(x )

I consider %4 a correct answer, and all the rest as junk (or course,
%5 is just a corollary of %3 and %6).  What do you think?

Ilya