Which nations have both hosts of age above 45 and hosts of age below 35?
return nations ;return hosts  of #1 ;return ages of #2 ;return #1 where at least one #3 is  above 45 ;return #1 where at least one #3 is  below 35 ;return #1 in both #4 and #5
['select', 'project', 'project', 'comparative', 'comparative', 'intersection']