If there is a mirror positioned above every sink basin.
return mirrors ;return sink basins ;return #1 positioned above #2 ;return number of  #3 for each  #2 ;return #2 where  #4 is at least one ;return number of  #2 ;return number of  #5 ;return if  #7 is equal to  #6
['select', 'select', 'filter', 'group', 'comparative', 'aggregate', 'aggregate', 'boolean']