What are the names of all schools that have students trying out for the position of goal and 'mid'-field.
return schools ;return students of  #1 ;return positions #2 are  trying out for ;return #1 where #3 is  goal ;return #1 where #3 is  'mid'-field ;return #1 of  both #4 and  #5 ;return names of  #6
['select', 'project', 'project', 'comparative', 'comparative', 'intersection', 'project']