1 files changed, 4 insertions, 3 deletions
diff --git a/main.cpp b/main.cpp
index eae0597..68f6c33 100644
--- a/main.cpp
+++ b/main.cpp
@@ -8,10 +8,11 @@
 #ifdef DEBUG
 extern Cons *empty_list;
 void tree_print(Cons *ptr) {
-    if (!ptr || ptr == empty_list) return;
     ptr->_debug_print();
-    tree_print(dynamic_cast<Cons*>(ptr->car));
-    tree_print(TO_CONS(ptr->cdr));
+    if (ptr->car->is_cons_obj())
+        tree_print(TO_CONS(ptr->car));
+    if (ptr->cdr->is_cons_obj())
+        tree_print(TO_CONS(ptr->cdr));
 }
 #endif