Derivative of O(x^0)
Consider a power series
R.<x> = PowerSeries(SR) f = 1 + O(x^2) f.derivative()
This gives us
O(x^1) as we would expect. However, if we do
f = O(x^0) f.derivative()
O(x^-1) instead of
O(x^0) again. Is this a bug or am I missing something?