diff --git a/preliminaries/motifs-and-structral-roles_lecture.md b/preliminaries/motifs-and-structral-roles_lecture.md
index 1a970fa..8f6672a 100755
--- a/preliminaries/motifs-and-structral-roles_lecture.md
+++ b/preliminaries/motifs-and-structral-roles_lecture.md
@@ -1,8 +1,7 @@
 ---
 layout: post
 title: Motifs and Structral Rules in Network
-header-includes:
-   - \usepackage{amsmath}
+
 ---
 
 ## Subgraphs