Fixed minor bug

Author: ajratner

snorkel/lf_helpers.py

@@ -55,7 +55,7 @@ def is_inverted(c):
     """Returns True if the ordering of the candidates in the sentence is inverted."""
     if len(c.get_arguments()) != 2:
         raise ValueError("Only applicable to binary Candidates")
-    return span0.get_word_start() > span1.get_word_start()
+    return c[0].get_word_start() > c[1].get_word_start()
 
 
 def get_between_tokens(c, attrib='words', n_max=1, case_sensitive=False):