Edit detail for Test revision 9 of 16

integrate((x^2-1)*arctan(a*x),x)

   There are no library operations named arctan 
      Use HyperDoc Browse or issue
                               )what op arctan
      to learn if there is any operation containing " arctan " in its 
      name.

   Cannot find a definition or applicable library operation named 
      arctan with argument type(s) 
                             Polynomial(Integer)

      Perhaps you should use "@" to indicate the required return type, 
      or "$" to specify which version of the function you need.