Is the number of spheres equal to the number of objects that are made of the same material as the purple object?
return spheres ;return purple object ;return objects besides #2 ;return material of #2 ;return materials of #3 ;return #3 where #5 Is the    same as #4 ;return number of #1 ;return number of #6 ;return Is #7 the    same as #8
['select', 'select', 'discard', 'project', 'project', 'comparative', 'aggregate', 'aggregate', 'boolean']