The function TSum(a;b) calculates the sum of the times in the results with IDs a to b.
TSum(10;12) - equivalent to nz(T10)+nz(T11)+nz(T12)
The function TSum(a;b;c;d) retrieves all times in the results with IDs a to b, sorts them from smallest to largest and then calculates the sum of the best results from positions c to d.
TSum(10;15;1;2) - sums the two best times of the results 10 to 15. TSum(10;15;3;3) - returns the third best time of the results 10-15.
TSum(a;b;c;d;1) corresponds to TSum(a;b;c;d), but sorts the times in descending order.