diff --git a/abducer/abducer_base.py b/abducer/abducer_base.py
index 83826a6..63a3c73 100644
--- a/abducer/abducer_base.py
+++ b/abducer/abducer_base.py
@@ -110,11 +110,13 @@ class AbducerBase(abc.ABC):
         address_idx_list = list(combinations(list(range(len(pred_res))), address_num))
         for address_idx in address_idx_list:
             for c in all_address_candidate:
-                pred_res_array = np.array(pred_res)
-                if np.count_nonzero(np.array(c) != pred_res_array[np.array(address_idx)]) == address_num:
-                    pred_res_array[np.array(address_idx)] = c
-                    if self.kb.logic_forward(pred_res_array) == key:
-                        new_candidates.append(pred_res_array)
+                address_list = [pred_res[i] for i in address_idx]
+                if(sum([address_list[i] == c[i] for i in range(address_num)]) == 0):
+                    candidate = pred_res.copy()
+                    for i, idx in enumerate(address_idx):
+                        candidate[idx] = c[i]
+                    if self.kb.logic_forward(candidate) == key:
+                        new_candidates.append(candidate)
         return new_candidates
     
     def get_abduce_candidates(self, pred_res, key, max_address_num, require_more_address):