diff --git a/report.tex b/report.tex
index 42b162c..02ce10d 100644
--- a/report.tex
+++ b/report.tex
@@ -576,7 +576,7 @@
         \pt{\tensor{\psi}{_i}} = \Partial{_i} \pi.
       \end{cases}
     \end{equation}
-    write $u^I = (\phi, \pi, \tensor{\psi}{_1}, \tensor{\psi}{_2}, \tensor{\psi}{_3})$, then the system can be written in the form of~\eqref{first-order-PDE} with
+    write $u^I = (\phi, \pi, \tensor{\psi}{_1}, \tensor{\psi}{_2}, \tensor{\psi}{_3})^T$, then the system can be written in the form of~\eqref{first-order-PDE} with
     \begin{equation}
       \tensor{A}{^i^I_J} = \begin{pmatrix}
         0 & 0 & 0 \\