diff --git a/main/math.tex b/main/math.tex
index d0bf5f8..cdd9a6d 100644
--- a/main/math.tex
+++ b/main/math.tex
@@ -26,6 +26,8 @@
 \newcommand{\Rightarrowequiv}{\overset{\cdot}{\Rightarrow}}
 \newcommand{\Leftarrowequiv}{\overset{\cdot}{\Leftarrow}}
 \newcommand{\defAs}{\overset{\text{def}}{=}}
+\newcommand{\der}[1]{\frac{\mbox{d}}{\mbox{d}#1}}
+\newcommand{\dern}[2]{\frac{\mbox{d}^{#2}}{\mbox{d}^{#2}#1}}
 \newcommand{\defEquiv}{\overset{\text{def}}{\Leftrightarrow}}
 \newcommand{\defImplies}{\overset{\text{def}}{\Rightarrow}}
 \newcommand{\divides}{\hspace{0.25em}|\hspace{0.25em}}