module MultiModuleIn1 where
f :: [Int] -> Int
 
f ((y : ys))
    =   case ys of
            ys@[] -> (head ys) + (head (tail ys))
            ys@(b_1 : b_2) -> (head ys) + (head (tail ys))
f ((y : ys)) = (head ys) + (head (tail ys))
 