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diff --git a/code/calculator/calc2.ml b/code/calculator/calc2.ml
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+++ b/code/calculator/calc2.ml
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+(* calc1.ml, enhanced with Function Values *)
+
+	type term =
+		  Intconstant of int
+		| Multiplication of (term * term)
+		| Addition of (term * term)
+		| Variable of char
+		| Let of (char * term * term)
+		| Iszero of term
+		| If of (term * term * term)
+		| Makepair of (term * term)
+		| First of term
+		| Lambda of (char * term)
+		| Apply of (term * term)
+        ;;
+
+    type bound_value = expressed_value
+	and assignment = (char * bound_value) list
+    and expressed_value = Int of int | Bool of bool | Pair of expressed_value * expressed_value | Closure of char * term * assignment;;
+
+	let rec eval (t : term) (g : assignment) = match t with
+	  Intconstant x -> Int x
+	| Multiplication (t1, t2) ->
+		(* we don't handle cases where the subterms don't evaluate to Ints *)
+		let Int i1 = eval t1 g
+		in let Int i2 = eval t2 g
+		(* Multiplication (t1, t2) should evaluate to an Int *)
+		in Int (i1 * i2)
+	| Addition (t1, t2) ->
+		let Int i1 = eval t1 g
+		in let Int i2 = eval t2 g
+		in Int (i1 + i2)
+	| Variable (var) ->
+		(* we don't handle cases where g doesn't bind var to any value *)
+		List.assoc var g
+	| Let (var_to_bind, t2, t3) ->
+		(* evaluate t3 under a new assignment where var_to_bind has been bound to
+		   the result of evaluating t1 under the current assignment *)
+		let value2 = eval t2 g
+		in let g' = (var_to_bind, value2) :: g
+		in eval t3 g'
+	| Iszero (t1) ->
+		(* we don't handle cases where t1 doesn't evaluate to an Int *)
+		let Int i1 = eval t1 g
+		(* Iszero t1 should evaluate to a Bool *)
+		in Bool (i1 = 0)
+	| If (t1, t2, t3) ->
+		(* we don't handle cases where t1 doesn't evaluate to a boolean *)
+		let Bool b1 = eval t1 g
+		in if b1 then eval t2 g
+		else eval t3 g
+	| Makepair (t1, t2) ->
+		let value1 = eval t1 g
+		in let value2 = eval t2 g
+		in Pair (value1, value2)
+	| First (t1) ->
+		(* we don't handle cases where t1 doesn't evaluate to a Pair *)
+		let Pair (value1, value2) = eval t1 g
+		in value1
+	| Lambda (arg_var, t2) -> Closure (arg_var, t2, g)
+	| Apply (t1, t2) ->
+		(* we don't handle cases where t1 doesn't evaluate to a function value *)
+		let Closure (arg_var, body, savedg) = eval t1 g
+		in let value2 = eval t2 g
+		(* evaluate body under savedg, except with arg_var bound to value2 *)
+		in let savedg' = (arg_var, value2) :: savedg
+		in eval body savedg'
+    ;;