diff --git a/chapters/classes.tex b/chapters/classes.tex
index d26725058..7b3484e6a 100644
--- a/chapters/classes.tex
+++ b/chapters/classes.tex
@@ -1142,11 +1142,11 @@ \section{Balanced Models}\doublelabel{balanced-models}
 
 %TODO-FORMAT Should this be verbatim code instead?
 Local equations:
-\begin{eqnarray*}
-0 &=& p.i + n.i;\\
-u &=& p.v - n.v;\\
-C \cdot \text{der}(u) &=& p.i;
-\end{eqnarray*}
+\begin{align*}
+0 &= p.i + n.i;\\
+u &= p.v - n.v;\\
+C \cdot \text{der}(u) &= p.i;
+\end{align*}
 and 2 equations corresponding to the 2 flow-variables \lstinline!p.i! and \lstinline!n.i!.
 
 These are 5 equations in 5 unknowns (\textbf{locally}
@@ -1213,13 +1213,13 @@ \section{Balanced Models}\doublelabel{balanced-models}
 flow variables for \lstinline!t! (\lstinline!t.p.i!, \lstinline!t.n.i!), and 2 flow variables for \lstinline!c! (\lstinline!c.p.i!, \lstinline!c.n.i!).
 
 Local equations:
-\begin{eqnarray*} \text{p.v} &=& \text{t.p.v};\\
-0 &=& \text{p.i}-\text{t.p.i};\\
-\text{c.p.v} &=& \text{t.n.v};\\
-0 &=& \text{c.p.i}+\text{t.n.i};\\
-\text{n.v} &=& \text{c.n.v};\\
-0 &=& \text{n.i}-\text{c.n.i};
-\end{eqnarray*}
+\begin{align*} \text{p.v} &= \text{t.p.v};\\
+0 &= \text{p.i}-\text{t.p.i};\\
+\text{c.p.v} &= \text{t.n.v};\\
+0 &= \text{c.p.i}+\text{t.n.i};\\
+\text{n.v} &= \text{c.n.v};\\
+0 &= \text{n.i}-\text{c.n.i};
+\end{align*}
 and 2 equation corresponding to the flow variables \lstinline!p.i!, \lstinline!n.i!.
 
 In total we have 8 scalar unknowns and 8 scalar equations, i.e., a
diff --git a/chapters/operatorsandexpressions.tex b/chapters/operatorsandexpressions.tex
index 5c0d03677..a14723882 100644
--- a/chapters/operatorsandexpressions.tex
+++ b/chapters/operatorsandexpressions.tex
@@ -714,11 +714,11 @@ \subsubsection{spatialDistribution}\doublelabel{spatialdistribution}
 The \lstinline!spatialDistribution!() operator allows to approximate efficiently the
 solution of the infinite-dimensional problem
 
-\begin{eqnarray*}
-\frac{\partial z(y,t)}{\partial t}+v(t)\frac{\partial z(y,t)}{\partial y}&=&0.0\\
-z(0.0, t)=\mathrm{in}_0(t) \text{ if $v\ge 0$}\\
-z(1.0, t)=\mathrm{in}_1(t) \text{ if $v<0$}
-\end{eqnarray*}
+\begin{align*}
+\frac{\partial z(y,t)}{\partial t}+v(t)\frac{\partial z(y,t)}{\partial y} &= 0.0\\
+z(0.0, t) &= \mathrm{in}_0(t) \text{ if $v\ge 0$}\\
+z(1.0, t) &= \mathrm{in}_1(t) \text{ if $v<0$}
+\end{align*}
 where $z(y, t)$ is the transported quantity, $y$ is the
 normalized spatial coordinate ($0.0 \le y \le 1.0$), $t$ is the
 time, $v(t)=\mathrm{der}(x)$ is the normalized