If there are two zebras and blue sky visible in the left image.
return sky ;return #1 that is  blue ;return if  #2 is  in  the  left image ;return zebras ;return #4 in  the  left image ;return number of #5 ;return if  #6 is  equal to two ;return if  both  #3 and #7 are  true
['select', 'filter', 'boolean', 'select', 'filter', 'aggregate', 'boolean', 'boolean']