diff --git a/py_ecc/bn128/bn128_field_elements.py b/py_ecc/bn128/bn128_field_elements.py
index 86d6a82..4359fd1 100644
--- a/py_ecc/bn128/bn128_field_elements.py
+++ b/py_ecc/bn128/bn128_field_elements.py
@@ -112,7 +112,7 @@ def zero(cls):
 # Utility methods for polynomial math
 def deg(p):
     d = len(p) - 1
-    while p[d] == 0 and d:
+    while p[d] == 0 and d:# eliminates zero coefficients
         d -= 1
     return d