diff --git a/bin/main.ml b/bin/main.ml
index 86c7546..21c2600 100644
--- a/bin/main.ml
+++ b/bin/main.ml
@@ -5,13 +5,12 @@ let colorred s =
 
 let () =
   let program = "
-def main with input n output result as
-    result := 0;
-    s := 0;
-    while (0 == ((n - 1) / (2 ^ s)) % 2) do (
-      s := s + 1
+def main with input n output out as
+    for (x := 2, x < 0, x := 2) do (
+      y := x + 3;
+      x := y;
     );
-
+    out := 1 - y;
 "
   in
 
diff --git a/lib/miniImp/definedVariables.ml b/lib/miniImp/definedVariables.ml
index 919771b..0c2a86b 100644
--- a/lib/miniImp/definedVariables.ml
+++ b/lib/miniImp/definedVariables.ml
@@ -18,6 +18,32 @@ module DVCfg = Dataflow.Make (CfgRISC.RISCSimpleStatements) (Variable)
 module DVCeltSet = Set.Make(Variable)
 
 
+let variables (instr : DVCfg.elt) : DVCfg.internal list =
+  let helper (acc: DVCeltSet.t) (instr: DVCfg.elt) =
+    match instr with
+    | Nop ->
+      acc
+    | BRegOp (_, r1, r2, r3) ->
+      DVCeltSet.add r1.index acc |>
+      DVCeltSet.add r2.index |>
+      DVCeltSet.add r3.index
+    | BImmOp (_, r1, _, r3)
+    | URegOp (_, r1, r3)
+    | Load (r1, r3)
+    | Store (r1, r3) ->
+      DVCeltSet.add r1.index acc |>
+      DVCeltSet.add r3.index
+    | LoadI (_, r3) ->
+      DVCeltSet.add r3.index acc
+  in
+
+  helper DVCeltSet.empty instr |> DVCeltSet.to_list
+
+let variables_all (instructions : DVCfg.elt list) : DVCfg.internal list =
+  List.fold_left (fun (acc: DVCeltSet.t) (instr: DVCfg.elt) ->
+      DVCeltSet.union acc (variables instr |> DVCeltSet.of_list)
+    ) DVCeltSet.empty instructions |> DVCeltSet.to_list
+
 let variables_used (instr : DVCfg.elt) : DVCfg.internal list =
   let helper (acc: DVCeltSet.t) (instr: DVCfg.elt) =
     match instr with
@@ -62,21 +88,21 @@ let variables_defined_all (instructions : DVCfg.elt list) : DVCfg.internal list
       DVCeltSet.union acc (variables_defined instr |> DVCeltSet.of_list)
     ) DVCeltSet.empty instructions |> DVCeltSet.to_list
 
-let _variables_defined_nth (instructions : DVCfg.elt list) (i: int) : DVCfg.internal list =
-  variables_defined (List.nth instructions i)
-
-let _variables_defined_last (instructions : DVCfg.elt list) : DVCfg.internal list =
-  variables_defined (List.nth instructions ((List.length instructions) - 1))
 
 
-
-
-(* init function, assign the epmpty set to everything *)
-let init : (DVCfg.elt list -> DVCfg.internalnode) =
+(* init function, assign the bottom to everything *)
+let _init_bottom : (DVCfg.elt list -> DVCfg.internalnode) =
   (fun l -> {internalin = [];
              internalout = [];
              internalbetween = (List.init (List.length l) (fun _ -> ([], [])))})
 
+(* init function, assign the top to everything *)
+let init_top (all_variables) : (DVCfg.elt list -> DVCfg.internalnode) =
+  (fun l -> {internalin = all_variables;
+             internalout = all_variables;
+             internalbetween = (List.init (List.length l)
+                                  (fun _ -> (all_variables, all_variables)))})
+
 
 (* piece of code that computes vout for the whole block, not used,
    use lub below *)
@@ -171,8 +197,13 @@ let update (t: DVCfg.t) (node: Cfg.Node.t) : DVCfg.internalnode =
 
 
 let compute_defined_variables (cfg: RISCCfg.t) : DVCfg.t =
+  let all_variables = List.fold_left
+      (fun acc (_, code) -> Utility.unique_union acc (variables_all code))
+      []
+      (Cfg.NodeMap.to_list cfg.content)
+  in
   DVCfg.from_cfg cfg
-  |> DVCfg.fixed_point ~init:init ~update:update
+  |> DVCfg.fixed_point ~init:(init_top all_variables) ~update:update