If the two zebras are standing together in the field resting their heads on one another.
return zebras ;return field ;return #1 that are standing together ;return #3 that are in  #2 ;return heads of #4 ;return #4 that are resting #5 on one another ;return number of  #6 ;return if  #7 is equal to  two
['select', 'select', 'filter', 'filter', 'project', 'filter', 'aggregate', 'boolean']