What are the ids of all reviewers who have not given 4 stars at least once?
return reviewers ;return 4 stars that  #1 have given ;return number of  #2 for each #1 ;return #1 where #3 is  at least one ;return #1 besides #4 ;return the  ids of #5
['select', 'project', 'group', 'comparative', 'discard', 'project']