When I download the help document here
https://www.maplesoft.com/support/help/maple/view.aspx?path=int%2Fdetails
I get a bug when I execute the page.
I copied pasted the last line using 1d math notation to replicate the error.
There is no addition symbol between x^2 + O(x^5)
On the help page I don't see an error.
I uploaded the help file int-details_(2).mw