diff --git a/src/restrictions.erl b/src/restrictions.erl
index 5bd5866..9bd8982 100644
--- a/src/restrictions.erl
+++ b/src/restrictions.erl
@@ -147,7 +147,7 @@ max_args(Args) ->
         true ->
             true;
         false ->
-            sandbox:restricted()
+            sandbox:restricted_msg()
     end.
 
 max_heap_size() ->
@@ -156,5 +156,5 @@ max_heap_size() ->
         true ->
             true;
         false ->
-            sandbox:restricted()
+            sandbox:restricted_msg()
     end.
diff --git a/src/sandbox.erl b/src/sandbox.erl
index d0a3f68..2c1e61e 100644
--- a/src/sandbox.erl
+++ b/src/sandbox.erl
@@ -6,6 +6,8 @@
 
 -define(MAX_HEAP_SIZE, 10000).
 -define(MAX_ARGS_SIZE, 200).
+-define(MAX_SIZE_QUALIFIER_DIMENSION, 500).
+-define(MAX_SPACE_DIMENSION,1000).
 
 -define(ATOM_PREFIX, "axwlefhubay_").
 
@@ -15,8 +17,9 @@ eval(E) ->
 eval(E, Bs) ->
     {ok, Tokens, _} = erl_scan:string(E),
     {ok, Exprs} = erl_parse:parse_exprs(Tokens),
+    put(bindings,Bs),
     SafeExprs = safe_exprs(Exprs),
-    {value, Value, NBs} = erl_eval:exprs(SafeExprs, Bs, {eval, fun lh/3}, {value, fun nlh/2}),
+    {value, Value, NBs} = erl_eval:exprs(SafeExprs, get(bindings), {eval, fun lh/3}, {value, fun nlh/2}),
     {erl_syntax:concrete(restore_exprs(erl_syntax:abstract(Value))),
      erl_syntax:concrete(restore_exprs(erl_syntax:abstract(NBs)))}.
 
@@ -27,9 +30,9 @@ lh(f, [{var,_,Name}], Bs) ->
 lh(F, Args, Bs) ->
     Arity = length(Args),
     case erlang:function_exported(user_default, F, Arity) of
-	true ->
+true ->
             {eval, erlang:make_fun(user_default, F, Arity), Args, Bs};
-	false ->
+false ->
             {value, sandbox:restricted_msg(), Bs}
     end.
 
@@ -85,11 +88,54 @@ safe_application(Node) ->
         fun_expr ->
             sandbox:restricted_msg();
         size_qualifier ->
-            sandbox:restricted_msg();
-        _ ->
+            SubTree = erl_syntax:size_qualifier_argument(Node),
+            {value, Value, NBs} = erl_eval:exprs([revert(SubTree)], get(bindings), {eval, fun lh/3}, {value, fun nlh/2}),
+            if
+                Value < ?MAX_SIZE_QUALIFIER_DIMENSION, is_integer(Value) ->
+                    [First, _] = erl_syntax:subtrees(Node),
+                    put(bindings,NBs),
+                    erl_syntax:update_tree(Node,[First,[{integer,1,Value}]]);
+                true ->
+                    sandbox:restricted_msg()
+            end;
+        list_comp ->
+            ListCompBody = erl_syntax:list_comp_body(Node),
+            SpaceDimension = calculateSpaceDimension(ListCompBody),
+            case SpaceDimension =< ?MAX_SPACE_DIMENSION of
+                true ->
+                    Node;
+                false ->
+                    sandbox:restricted_msg()
+            end;
+        binary_comp ->
+            BinaryCompBody = erl_syntax:binary_comp_body(Node),
+            SpaceDimension = calculateSpaceDimension(BinaryCompBody),
+            case SpaceDimension =< ?MAX_SPACE_DIMENSION of
+                true ->
+                    Node;
+                false ->
+                    sandbox:restricted_msg()
+            end;
+        _Else ->
             Node
     end.
 
+calculateSpaceDimension(ListCompBody)->
+    calculateSpaceDimension(ListCompBody,1).
+
+calculateSpaceDimension([],Acc)->
+    Acc;
+calculateSpaceDimension([H|T],Acc)->
+    H1 = restore_expr(H),
+    case erl_syntax:type(H1) of
+    generator ->
+        [_Var,List] = erl_syntax:subtrees(H1),
+        {value, Value, _NBs} = erl_eval:exprs(revert(List), get(bindings), {eval, fun lh/3}, {value, fun nlh/2}),
+        calculateSpaceDimension(T,Acc*length(Value));
+    _ ->
+        calculateSpaceDimension(T,Acc)
+    end.
+
 replace_atoms(Node) ->
     case erl_syntax:type(Node) of
         atom ->