diff --git a/Exercises/exercise-7/Lambda.hs b/Exercises/exercise-7/Lambda.hs
index 377ce8e..eeb4d32 100644
--- a/Exercises/exercise-7/Lambda.hs
+++ b/Exercises/exercise-7/Lambda.hs
@@ -40,3 +40,32 @@ pretty x = case x of
 -- (Lx.((x *z*) (Ly.(x y))))
 -- ((Lx.(x *z*)) Ly.(*w* (Lw.(((w y) *z*) *x*))))
 -- Lx.((x "y") (Lx.("y" x)))
+
+--------------------
+-- Exercise 4
+--------------------
+----------
+-- 1.)
+----------
+-- (((Lz.z) (Ly.yy)) (Lx.xa))
+-- ((Ly.yy) (Lx.xa))
+-- (Lx.xa (Lx.xa))
+-- (Lx.xa) a
+-- (a a)
+
+----------
+-- 2.)
+----------
+-- (Lx.(x x))(Ly.(y x)) z
+-- (Ly.(y x)) (Ly.(y x)) z
+-- ((Ly.(y x)) x) z
+-- (x x) z
+-- x x z
+
+----------
+-- 3.)
+----------
+-- ((Lx.(x x))(Ly.y))(Ly.y)
+-- ((Ly.y Ly.y))(Ly.y)
+-- (Ly.y)(Ly.y)
+-- (Ly.y)