If all the animals are on four legs.
return animals ;return legs that #1 are on ;return number of  #2 for each  #1 ;return #1 where  #3 is equal to  four ;return number of  #1 ;return number of  #4 ;return if  #5 is equal to  #6
['select', 'project', 'group', 'comparative', 'aggregate', 'aggregate', 'boolean']