If there is one person holding at least one dog.
return people ;return dogs ;return #1 holding #2 ;return number of #2 for each #3 ;return #3 where #4 is  at least one  ;return number of #5 ;return if  #6 is  equal to one
['select', 'select', 'filter', 'group', 'comparative', 'aggregate', 'boolean']