From d8c2cf7780ea62ae1484566dc813ae92ab5d0cee Mon Sep 17 00:00:00 2001
From: Timo Heister <timo.heister@gmail.com>
Date: Fri, 18 Jun 2021 18:01:01 -0400
Subject: [PATCH] step-66

---
 9.3/paper.tex | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/9.3/paper.tex b/9.3/paper.tex
index c748997..5627306 100644
--- a/9.3/paper.tex
+++ b/9.3/paper.tex
@@ -1057,7 +1057,8 @@ ways as part of this release. In addition, there are a number of new tutorial pr
   charged particles and an electric field, using a cathode tube as an
   example.
 
-\item \texttt{step-66} nonlinear matrix-free solver \todo[inline]{TODO}
+\item \texttt{step-66} shows how to solve a nonlinear problem using Newton's method in the matrix-free
+framework in parallel. The PDE considered is the Gelfand problem $-\triangle u = \exp(u)$.
   
 \item \texttt{step-68} is a demonstration of how to embed and distribute
   particles in a parallel triangulation. It tracks the movement of
-- 
2.39.5