If both stairways have glass sides and wood handrails.
return stairways ;return sides of #1 ;return #1 where  #2 is glass ;return handrails of #3 ;return #3 where  #4 is wood ;return number of  #5 ;return if  #6 is equal to  two
['select', 'project', 'comparative', 'project', 'comparative', 'aggregate', 'boolean']