diff --git a/src/Evaluator.hs b/src/Evaluator.hs
index 668cbe6..22a31a1 100644
--- a/src/Evaluator.hs
+++ b/src/Evaluator.hs
@@ -15,8 +15,9 @@ base = M.fromList [
 
 eval :: Env -> Expr -> (Env, Expr)
 eval env (IntE x)      = (env, IntE x)
-eval env (VarE v)      = eval env $ env M.! v
-eval env (SetE v expr) = (M.insert v expr env, expr)
+eval env (VarE v)      = (M.insert v nExpr nEnv, nExpr)
+  where (nEnv, nExpr) = eval env $ env M.! v
+eval env (SetE v expr) = (M.insert v expr env, NilE)
 eval env NilE          = (env, NilE)
 
 --apply :: Proc -> Args -> Expr
diff --git a/src/ExprType.hs b/src/ExprType.hs
index 97635b5..704c06d 100644
--- a/src/ExprType.hs
+++ b/src/ExprType.hs
@@ -4,9 +4,9 @@ data Expr = IntE Integer
           | VarE String
           | ProcedureE String [Expr]
           | SetE String Expr
-          | NilE
+          | NilE deriving (Show)
 
-instance Show Expr where
-  show (IntE x) = show x
-  show (VarE x) = x ++ " ; var"
-  show NilE     = "nil"
+-- instance Show Expr where
+--   show (IntE x) = show x
+--   show (VarE x) = x ++ " ; var"
+--   show NilE     = "nil"