If all of the sailboats pictured a currently moored or a at a dock.
return sailboats ;return #1 that are currently moored ;return dock ;return #1 that are at #3 ;return #2 , #4 ;return number of  #1 ;return number of  #5 ;return if  #7 is equal to  #6
['select', 'filter', 'select', 'filter', 'union', 'aggregate', 'aggregate', 'boolean']