diff --git a/examples/02_construct_simple_pc.py b/examples/02_construct_simple_pc.py
index d69a4c9c..f17e6b76 100644
--- a/examples/02_construct_simple_pc.py
+++ b/examples/02_construct_simple_pc.py
@@ -49,7 +49,9 @@
 # :code:`ms` defines a product node vector where every node have two children: the first child is a node in :code:`ni0` and the second child is a node in :code:`ni1`.
 # :code:`edge_ids` specifies which child nodes do every node in :code:`ms` connects to. Specifically, :code:`edge_ids` has size :code:`[# product node blocks, # child node vectors]`, so in this case, it should has size :code:`[4, 2]`.
 # The semantic of :code:`edge_ids[i,j]` is:
-# the :math:`i`th product node block connects to the `edge_ids[i,j]`th node block in the jth child node vector (assume we always count from 0).
+# the :math:`i`th 
+# product node block connects to the :math:`edge_ids[i,j]`th 
+# node block in the jth child node vector (assume we always count from 0).
 # For example, `edge_ids[1,0] = 1` means that the 1th product node block connects to the 1th node block in :code:`ni0`.
 # 
 # We require the node vectors fed to :code:`pyjuice.multiply` have the same :code:`block_size`. And the block size of the output product node vector is also the same with that of the inputs.