diff --git a/boolean_algebra/quine_mc_cluskey.py b/boolean_algebra/quine_mc_cluskey.py
index 94319ca45482..def3df03ddb8 100644
--- a/boolean_algebra/quine_mc_cluskey.py
+++ b/boolean_algebra/quine_mc_cluskey.py
@@ -12,6 +12,12 @@
 
 	>>> selection([[1]],['0.00.01.5'])
 	['0.00.01.5']
+	
+	>>> compare_string('0110','1101')
+	-1
+	
+	>>> is_for_table('01_','001',1)
+	False
 """
 def compare_string(string1, string2):
 	l1 = list(string1); l2 = list(string2)