If at least one wolf is standing in front of trees with its head raised in a howling pose.
return wolves ;return trees ;return #1 standing in  front of #2 ;return heads of #3 ;return #3 where  #4 are raised in  a  howling pose ;return number of  #5 ;return if  #6 is at least one
['select', 'select', 'filter', 'project', 'comparative', 'aggregate', 'boolean']