If there are two beagles swimming and both of them have their heads above water.
return beagles ;return #1 that are swimming ;return the  number of  #2 ;return heads of #2 ;return water ;return #4 that are above #5 ;return the  number of  #6 ;return if  #3 is equal to  two ;return if  #7 is equal to  two ;return if  both  #8 and #9 is true
['select', 'filter', 'aggregate', 'project', 'select', 'filter', 'aggregate', 'boolean', 'boolean', 'boolean']