diff --git a/abducer/abducer_base.py b/abducer/abducer_base.py
index f26b363..93810c1 100644
--- a/abducer/abducer_base.py
+++ b/abducer/abducer_base.py
@@ -17,7 +17,6 @@ import abc
 from abducer.kb import add_KB, hwf_KB, add_prolog_KB
 import numpy as np
 
-from itertools import product, combinations
 import time
 
 class AbducerBase(abc.ABC):
@@ -26,7 +25,7 @@ class AbducerBase(abc.ABC):
         assert(dist_func == 'hamming' or dist_func == 'confidence')
         self.dist_func = dist_func        
         self.cache = cache
-        
+
         if self.cache:
             self.cache_min_address_num = {}
             self.cache_candidates = {}
@@ -83,21 +82,23 @@ class AbducerBase(abc.ABC):
 
     def abduce(self, data, max_address_num = -1, require_more_address = 0):
         pred_res, pred_res_prob, ans = data
+        if max_address_num == -1:
+            max_address_num = len(pred_res)
 
         if self.cache and (tuple(pred_res), ans) in self.cache_min_address_num:
             address_num = min(max_address_num, self.cache_min_address_num[(tuple(pred_res), ans)] + require_more_address)
             if (tuple(pred_res), ans, address_num) in self.cache_candidates:
                 candidates = self.cache_candidates[(tuple(pred_res), ans, address_num)]
-                candidate = self.get_min_cost_candidate(pred_res, pred_res_prob, candidates)
-                return candidate
+                return self.get_min_cost_candidate(pred_res, pred_res_prob, candidates)    
         
         candidates, min_address_num, address_num = self.kb.abduce_candidates(pred_res, ans, max_address_num, require_more_address)
         
+        
         if self.cache:
             self.cache_min_address_num[(tuple(pred_res), ans)] = min_address_num
             self.cache_candidates[(tuple(pred_res), ans, address_num)] = candidates
-
-        candidate = self.get_min_cost_candidate(pred_res, pred_res_prob, candidates)
+        
+        candidate = self.get_min_cost_candidate(pred_res, pred_res_prob, candidates)    
         return candidate
     
      
@@ -112,23 +113,34 @@ class AbducerBase(abc.ABC):
     
 
 if __name__ == '__main__':
+    prob1 = [[0, 0.99, 0.01, 0, 0, 0, 0, 0, 0, 0],[0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1]]
+    prob2 = [[0, 0, 0.01, 0, 0, 0, 0, 0.99, 0, 0],[0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1]]
+    
     kb = add_KB(GKB_flag = True)
-    abd = AbducerBase(kb, 'hamming')
-    res = abd.abduce(([1, 1], None, 17), max_address_num = 2, require_more_address = 0)
+    abd = AbducerBase(kb, 'confidence')
+    res = abd.abduce(([1, 1], prob1, 8), max_address_num = 2, require_more_address = 0)
+    print(res)
+    res = abd.abduce(([1, 1], prob2, 8), max_address_num = 2, require_more_address = 0)
+    print(res)
+    res = abd.abduce(([1, 1], prob1, 17), max_address_num = 2, require_more_address = 0)
     print(res)
-    res = abd.abduce(([1, 1], None, 17), max_address_num = 1, require_more_address = 0)
+    res = abd.abduce(([1, 1], prob1, 17), max_address_num = 1, require_more_address = 0)
     print(res)
-    res = abd.abduce(([1, 1], None, 20), max_address_num = 2, require_more_address = 0)
+    res = abd.abduce(([1, 1], prob1, 20), max_address_num = 2, require_more_address = 0)
     print(res)
     print()
     
     kb = add_prolog_KB()
-    abd = AbducerBase(kb, 'hamming')
-    res = abd.abduce(([1, 1], None, 17), max_address_num = 2, require_more_address = 0)
+    abd = AbducerBase(kb, 'confidence')
+    res = abd.abduce(([1, 1], prob1, 8), max_address_num = 2, require_more_address = 0)
+    print(res)
+    res = abd.abduce(([1, 1], prob2, 8), max_address_num = 2, require_more_address = 0)
+    print(res)
+    res = abd.abduce(([1, 1], prob1, 17), max_address_num = 2, require_more_address = 0)
     print(res)
-    res = abd.abduce(([1, 1], None, 17), max_address_num = 1, require_more_address = 0)
+    res = abd.abduce(([1, 1], prob1, 17), max_address_num = 1, require_more_address = 0)
     print(res)
-    res = abd.abduce(([1, 1], None, 20), max_address_num = 2, require_more_address = 0)
+    res = abd.abduce(([1, 1], prob1, 20), max_address_num = 2, require_more_address = 0)
     print(res)
     print()