step-37: Remove some unused header #includes.

diff --git a/examples/step-37/step-37.cc b/examples/step-37/step-37.cc
index a7ea2e6f79f89b6ec4c2ae5c5e9434630d7ea081..264c963d99ed84cfe5d7fa761702388d7eea0789 100644 (file)
--- a/examples/step-37/step-37.cc
+++ b/examples/step-37/step-37.cc
@@ -22,21 +22,16 @@
 // First include the necessary files from the deal.II library.
 #include <deal.II/base/quadrature_lib.h>
 #include <deal.II/base/function.h>
-#include <deal.II/base/logstream.h>
 #include <deal.II/base/timer.h>
 
 #include <deal.II/lac/affine_constraints.h>
-#include <deal.II/lac/full_matrix.h>
 #include <deal.II/lac/solver_cg.h>
 #include <deal.II/lac/la_parallel_vector.h>
 #include <deal.II/lac/precondition.h>
 
 #include <deal.II/fe/fe_q.h>
-#include <deal.II/fe/fe_values.h>
 
 #include <deal.II/grid/tria.h>
-#include <deal.II/grid/tria_accessor.h>
-#include <deal.II/grid/tria_iterator.h>
 #include <deal.II/grid/grid_generator.h>
 
 #include <deal.II/multigrid/multigrid.h>