Sums elements of r, which must be a finite
iterable.
A seed may be passed to sum. Not only will this seed be used as an initial
value, but its type will be used if it is not specified.
Note that these specialized summing algorithms execute more primitive operations
than vanilla summation. Therefore, if in certain cases maximum speed is required
at expense of precision, one can use Summation.fast.
Sums elements of r, which must be a finite iterable.
A seed may be passed to sum. Not only will this seed be used as an initial value, but its type will be used if it is not specified.
Note that these specialized summing algorithms execute more primitive operations than vanilla summation. Therefore, if in certain cases maximum speed is required at expense of precision, one can use Summation.fast.