From be29d834d3583b788b7ac4c57585a30444745d75 Mon Sep 17 00:00:00 2001
From: Krishnakumar Gopalakrishnan <krishna.kumar@ucl.ac.uk>
Date: Fri, 17 Jan 2020 15:00:26 +0000
Subject: [PATCH] In step-10, fixes explanation surrounding new header
 inclusion. fixes 9356

---
 examples/step-10/step-10.cc | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/examples/step-10/step-10.cc b/examples/step-10/step-10.cc
index 36662569b3..4ee00fdebd 100644
--- a/examples/step-10/step-10.cc
+++ b/examples/step-10/step-10.cc
@@ -30,10 +30,14 @@
 #include <deal.II/grid/grid_out.h>
 #include <deal.II/dofs/dof_handler.h>
 #include <deal.II/dofs/dof_accessor.h>
-#include <deal.II/fe/fe_nothing.h>
 #include <deal.II/fe/fe_values.h>
 
-// This is the only new one: in it, we declare the MappingQ class
+// This include file is new. Even if we are not solving a PDE in this tutorial,
+// we want to use a dummy finite element with zero degrees of freedoms provided
+// by the FE_Nothing class.
+#include <deal.II/fe/fe_nothing.h>
+
+// The following header file is also new: in it, we declare the MappingQ class
 // which we will use for polynomial mappings of arbitrary order:
 #include <deal.II/fe/mapping_q.h>
 
-- 
2.39.5