Find the names of schools that have some students playing in goalie and mid positions.
return schools ;return students of  #1 ;return positions of  #2 ;return #1 where  #3 is  goalie ;return #1 where  #3 is  mid ;return #1 of  both #4 and #5 ;return names of  #6
['select', 'project', 'project', 'comparative', 'comparative', 'intersection', 'project']