If the pig in the left image is heading left, and the pig in the right image is heading right.
return left  image  ;return pig of #1 ;return if  #2 is heading left  ;return right  image  ;return pig of #4 ;return if  #5 is heading right  ;return if  both  #3 and #6 is true
['select', 'project', 'boolean', 'select', 'project', 'boolean', 'boolean']