[Maxima] Numerical summation of series

[Michel Van den Bergh]

>
>> sum(1/(1+n^2),n,1,inf)
>>
>> numerically? Setting numer:true and applying float(-) did not seem to
>> have
>> any effect (except for replacing 1 by 1.0).
>>
>> The Levin u-transform is an often used method for summing such series
>
> It would be great if you could contribute this method to Maxima.
>
>             -s
I will give it a try. But I am not very familiar with the conventions in
Maxima. How do you specify for example the required precision of a
numerical operation? How do you signal an error (such as division by zero)?

Regards,
Michel