If one image contains no more than 4 pigs.
return images ;return pigs in  #1 ;return number of  #2 for each  #1 ;return #1 where  #3 is at most 4 ;return number of  #4 ;return if  #5 is equal to  one
['select', 'project', 'group', 'comparative', 'aggregate', 'boolean']