Which student's age is older than 18 and is majoring in 600? List each student's first and last name.
return students ;return major of #1 ;return #1 where #2 is equal to 600 ;return ages of #3 ;return #3 where #4 is higher than 18 ;return first names of #5 ;return last names of #5 ;return #6 ,  #7
['select', 'project', 'comparative', 'project', 'comparative', 'project', 'project', 'union']