> And it does, at least if you mean this by "the 3rd example": > (enum-set-subset? (c '(red blue)) e) Sorry for the confusion, I meant the 3rd example using enum-set-subset?, in other words: (enum-set-subset? (c '(red blue)) (c '(red))) => #f But I feel that should be #t as both universe of either value is the same.