what is the phone number of employees whose salary is in the range of 8000 and 12000?
return employees ;return salaries of  #1 ;return #1 where #2 is  at least 8000 ;return #1 where #2 is  at most 12000 ;return #1 of  both #3 and  #4 ;return phone numbers of  #5
['select', 'project', 'comparative', 'comparative', 'intersection', 'project']