Show all director names who have a movie in both year 1999 and 2000.
return directors ;return movies of #1 ;return years of #2 ;return #2 where #3 is  1999 ;return #2 where #3 is  2000 ;return the  number of  #4 for each #1 ;return the  number of  #5 for each #1 ;return #1 where #6 is  at least one ;return #1 where #7 is  at least one ;return #1 in both #8 and #9 ;return the  names of #10
['select', 'project', 'project', 'comparative', 'comparative', 'group', 'group', 'comparative', 'comparative', 'intersection', 'project']