I have a custom function that creates several tasks and assigns them to every potential in this list:

PotentialsList = zoho.crm.searchRecords("Potentials","(RunWorkFlow|=|True)",0,100);

I would need a second condition to be met: that the potential does not own any other task already assigned to it. 

Only Potentials with no Tasks should be included in the list.

How could I achieve the list of Potentials with no Tasks assigned?

Thanks in advance!