diff --git a/test_tex.tex b/test_tex.tex
index 4e4a043..8cc28cc 100644
--- a/test_tex.tex
+++ b/test_tex.tex
@@ -15,6 +15,7 @@
 
 \begin{document}
 \tagstructbegin{tag=Document}
+\LuaMMLTagAF{} {
 \[
   \begin{pmatrix}
     1 & 0 & 0 \\
@@ -27,12 +28,17 @@
     2 & $else$
   \end{cases}
 \]
+}
+\LuaMMLTagAF{} {
 \[
   x = \frac{-b \pm \sqrt{b^2-4ac}}{2a}.
 \]
+}
+\LuaMMLTagAF{} {
 \[
   \sum_a\underline c\dot bc'
 \]
+}
 
 \LuaMMLTagAF{} {
 \begin{align}