diff --git a/cfg_utils.py b/cfg_utils.py
index 705d893116313846c011db956b90becb8719ef2f..4de2989b6ad6be5ab3889ef691bdd95232b798af 100644
--- a/cfg_utils.py
+++ b/cfg_utils.py
@@ -550,11 +550,12 @@ class CFGBoltzmann:
     # X_ijk is not the last  |        Case B             |         Case D               |
     # symbol in the          | A terminal always has len | Like the convolution, but use|
     # production rule (i,j)  | 1 and no possibilities so | Fprim and weighted-choice on |
-    #                        | this reduces to           | X_ijk to find out how many   |
-    #                        | Gprim(i, j, k+1, N-1)     | symbols we're having X_ijk   |
-    #                        |                           | generate (then use Gzero on  |
-    #                        |                           | X_ijk and Gprim on k+1 to end|
-    #                        |                           | of the rule                  |
+    #                        | this reduces to           | [X_ijk, last symbol in the   |
+    #                        | Gprim(i, j, k+1, N-1)     | production rule] to find out |
+    #                        |                           | how many symbols we're having|
+    #                        |                           | X_ijk generate. Then we use  |
+    #                        |                           | Gzero on X_ijk and Gprim on  |
+    #                        |                           | (k+1) to end of rule         |
     #                        \----------------------------------------------------------/