Find the name and gender of the staff who has been assigned the job of Sales Person but never Clerical Staff.
return staffs ;return jobs assigned to  #1 ;return #1 where at least one #2 is  Sales Person ;return #1 where at least one #2 is  Clerical Staff ;return #1 in both #3 and #4 ;return #3 besides #5 ;return the   names of #6 ;return the   genders of #6 ;return #7 ,  #8
['select', 'project', 'comparative', 'comparative', 'intersection', 'discard', 'project', 'project', 'union']