diff --git a/algo.py b/algo.py
index 67f728b086d776dde4d78bb82c56c2a6fa88a290..409838756317dd574dac54e8856c8d463ac1ba47 100644
--- a/algo.py
+++ b/algo.py
@@ -79,7 +79,7 @@ def exponentiation_rapide(a, exp, n):
 
 
 def is_square(a):
-    """Check if a number is a perfect square, based on the "Babylonian algorithm" for square root,
+    """Check if a number is a perfect square, based on the "Babylonian algorithm" (Héron's method) for square root,
     from : https://stackoverflow.com/questions/2489435/check-if-a-number-is-a-perfect-square 
         
     Args:
@@ -93,7 +93,7 @@ def is_square(a):
     seen = set([x])
     
     while x * x != a:
-        x = (x + (a // x)) // 2
+        x = (x + (a // x)) // 2 # arithmetic average
         
         if x in seen: 
             return False
@@ -131,6 +131,7 @@ def fermat_factorization(n):
     b = int(math.sqrt(b2))
     return (a, b)
 
+
 def decode_msg(M):
     """Decode a code UTF-8 in characters
     from : Niklaus Eggenberg