if true X Y X if false U V V filter I nil nil filter J cons X1 Y1 if J X1 cons X1 filter J Y1 filter J Y1 X c Y c U c V c I a b J a b X1 a Y1 c cons a c c false b filter a b c c if b c c c nil c true b FULL benchmarks/applicative/AotoYamada_05__015.atrs