Find the names of the swimmers who have both "win" and "loss" results in the record.
return swimmers ;return results of #1 ;return #1 where #2 is win ;return #1 where #2 is loss ;return #1 in  both #3 and  #4 ;return names of #5
['select', 'project', 'comparative', 'comparative', 'intersection', 'project']