I never heard of apl's allowing for an explicit choice of initial value, nor direction control ('from-end'), which mls typically also provide (foldl vs foldr).

I never heard of apl's allowing for an explicit choice of initial value, nor direction control ('from-end'), which mls typically also provide (foldl vs foldr). On the other hand, the ad-hoc choice of result for an empty input is a flaw common to cl and apl.