diff --git a/src-java/Interpreter.java b/src-java/Interpreter.java
index a1c69b0..11d6fa3 100644
--- a/src-java/Interpreter.java
+++ b/src-java/Interpreter.java
@@ -44,8 +44,9 @@ public class Interpreter {
       // p.listident_
       // abstract over arguments from right to left
       // f x1 ... xn = e  =====>  f = \ x1 -> ... \ xn -> e
-      // Collections.reverse(p.listident_);
-
+      Collections.reverse(p.listident_);
+      for (String x : p.listident_)
+        e = new EAbs(x, e);
       sig.put(p.ident_, e);
       return null;
     }
@@ -72,8 +73,7 @@ public class Interpreter {
   // env |- e ==> v
 
   public Value eval(Exp e, Environment env) {
-    todo("eval");
-    return null;
+    return e.accept (new EvalVisitor (), env);
   }
 
   public class EvalVisitor implements Exp.Visitor<Value,Environment>
@@ -82,9 +82,7 @@ public class Interpreter {
     // literal
     public Value visit(fun.Absyn.EInt p, Environment env)
     {
-      // p.integer_
-      todo("literal");
-      return null;
+      return new VInt(p.integer_);
     }
 
     // Variable (call-by-value):
@@ -94,9 +92,12 @@ public class Interpreter {
     //
     public Value visit(fun.Absyn.EVar p, Environment env)
     {
-      // p.ident_
-      todo("var");
-      return null;
+      try {
+        return env.lookup(p.ident_);
+      } catch (Unbound msg) {
+        Exp e = sig.get(p.ident_);
+        return evalClosed(e);
+      }
     }
 
     // Lambda:
@@ -106,24 +107,22 @@ public class Interpreter {
     //
     public Value visit(fun.Absyn.EAbs p, Environment env)
     {
-      // p.ident_ p.exp_
-      todo("abs");
-      return null;
+      return new VFun(p.ident_, p.exp_, env);
     }
 
     // Application (call-by-value):
     //
     //      env       |- e1 ==> let env' in \x -> f
     //      env       |- e2 ==> v2
-    //      env',x=v2 |- f ==> v
+    //      env',x=v2 |- f  ==> v
     //      ---------------------------------------
-    //      env |- e1 e2 ==> v
+    //      env       |- e1 e2 ==> v
     //
     public Value visit(fun.Absyn.EApp p, Environment env)
     {
-      // p.exp_1, p.exp_2
-      todo("app");
-      return null;
+      Value v1 = eval(p.exp_1, env);
+      Value v2 = eval(p.exp_2, env);
+      return v1.apply(v2);
     }
 
     // plus
@@ -177,8 +176,8 @@ public class Interpreter {
     }
 
     Value lookup (String y) throws Unbound {
-      todo("lookup");
-      return null;
+      if (y.equals(x)) return v;
+      else return env.lookup(y);
     }
   }
 
@@ -223,8 +222,7 @@ public class Interpreter {
     }
 
     public Value apply (Value v) {
-      todo("apply");
-      return null;
+      return eval(e, new Extend(x, v, env));
     }
   }