According to this elem is 

Eq a => a -> [a] -> Bool

but according to my ghci :t it's this

elem :: (Foldable t, Eq a) => a -> t a -> Bool

I understand the first, but not the second, especially with the t. What is this saying extra, different from the first one?



Lawrence Bottorff
Grand Marais, MN, USA
borgauf@gmail.com