If a dog has a front paw off the ground.
return dog ;return paw of #1 ;return #2 that is front ;return ground ;return #3 that is off #4 ;return #1 that has #5 ;return number of  #6 ;return if  #7 is at least one
['select', 'project', 'filter', 'select', 'filter', 'filter', 'aggregate', 'boolean']