If all four of the skates are covered partially or nearly entirely by sand.
return skates ;return sand ;return #1 covered partially by #2 ;return #1 covered nearly entirely by #2 ;return #3 ,   #4 ;return number of #5 ;return if  #6 is  equal to four
['select', 'select', 'filter', 'filter', 'union', 'aggregate', 'boolean']