If in this book store there is at least one person looking at  books from the shelve.
return book store ;return person in  #1 ;return books in  #1 ;return shelve in  #1 ;return #3 that are from  #4 ;return #2 that is looking at #5 ;return number of  #6 ;return if  #7 is at least one
['select', 'project', 'project', 'project', 'filter', 'filter', 'aggregate', 'boolean']