diff --git a/W1/calculator.fsx b/W1/calculator.fsx
index 53ef0ad..faf6de8 100644
--- a/W1/calculator.fsx
+++ b/W1/calculator.fsx
@@ -24,9 +24,6 @@ let rec lookup v = function
   | (v', k) :: vtab -> if v = v' then k else lookup v vtab
   | (_ : SymTab)    -> failwith ("unbound variable : " + v)
 
-(* HELP FUNCTIONS *)
-let VALUEtoint = function INT x -> x
-
 (* EVALUATION *)
 
 (*****************************************************
@@ -42,8 +39,8 @@ let rec eval (vtab : SymTab) (e : EXP) : VALUE =
     | VARIABLE v ->
       lookup v vtab
     | OPERATE (op, e1, e2) ->
-      let exp1 = VALUEtoint (eval vtab e1)
-      let exp2 = VALUEtoint (eval vtab e2)
+      let (INT exp1) = eval vtab e1
+      let (INT exp2) = eval vtab e2
       match op with
         | BPLUS -> INT (exp1 + exp2)
         | BMINUS -> INT (exp1 - exp2)
@@ -53,8 +50,8 @@ let rec eval (vtab : SymTab) (e : EXP) : VALUE =
       let vtab = bind var exp1 vtab
       eval vtab e2
     | OVER (rop, var, e1, e2, e3) ->
-      let exp1 = VALUEtoint (eval vtab e1)
-      let exp2 = VALUEtoint (eval vtab e2)
+      let (INT exp1) = eval vtab e1
+      let (INT exp2) = eval vtab e2
       let results = [
         for i in exp1..exp2 ->
           let vtab = bind var (INT i) vtab