mult :: Num a => [[a]] -> [[a]] -> [[a]]
mult uss vss =
let go xs
| null xs = []
| otherwise = foldl1 (zipWith (+)) xs
in go . zipWith (flip (map . (*))) vss <$> uss
main :: IO ()
main =
mapM_ print $
mult [[1, 2], [3, 4]] [[-3, -8, 3], [-2, 1, 4]]