diff --git a/07/Main.hs b/07/Main.hs
index 870bf13..eedfac6 100644
--- a/07/Main.hs
+++ b/07/Main.hs
@@ -20,6 +20,18 @@ int_plus_3 n = n + 3
 -- examples
 comp :: BigP -> Integer
 comp = int_plus_3 . bar
+-- same as: int_plus_3 $ bar $ P2 10
+
+double_arg :: Integer -> Integer -> Integer
+double_arg a b = a + b
+
+partially_applied :: Integer -> Integer
+partially_applied = double_arg 7
+
+
+func_arg :: (Integer -> Integer) -> Integer -> Integer
+func_arg f b = f b
+
 
 main :: IO ()
 main = putStrLn "Hello world"
diff --git a/07/Second.hs b/07/Second.hs
new file mode 100644
index 0000000..c4ee758
--- /dev/null
+++ b/07/Second.hs
@@ -0,0 +1,28 @@
+
+type Name = String
+type Table = [ (Name, Name) ]
+
+fathers :: Table
+fathers = [
+  ("a", "d"),
+  ("b", "r")
+  ]
+
+head' :: [a] -> a
+head' (x:xs) = x
+
+
+helper :: Integer -> [a] -> Integer
+helper acc (x:xs) = helper (acc + 1) xs
+helper acc ([]) = acc
+
+len' :: [a] -> Integer
+len' xs = helper 0 xs
+
+
+inv :: [a] -> [a]
+inv _ = _
+
+
+getF :: Name -> Maybe Name
+getF n = lookup n fathers