@@ -116,7 +116,7 @@ class RingWithUnity a => Field a where
116 inverseM : (x : a) -> Not (x = neutral) -> a
116 inverseM : (x : a) -> Not (x = neutral) -> a
118sum' : (Foldable t, Monoid a) => t a -> a
118sum' : (Foldable t, Monoid a) => t a -> a
119−sum' = foldr (<+>) neutral
119+sum' = concat
121product' : (Foldable t, RingWithUnity a) => t a -> a
121product' : (Foldable t, RingWithUnity a) => t a -> a
122product' = foldr (<.>) unity
122product' = foldr (<.>) unity