+AH_BOTTOM([#include <conf_post.h>])
+
+AC_ARG_WITH([gsl],
+ [AS_HELP_STRING([--with-gsl],
+ [specify whether to build test programs requiring the GNU Scientific Library. [default=auto]]
+ )], [with_gsl=$withval], [with_gsl=auto])
+
+AS_CASE([$with_gsl],
+ [no], [have_gsl=no],
+ [yes], [DX_CHECK_GSL([1.0], [have_gsl=yes])],
+ [DX_CHECK_GSL([1.0], [have_gsl=yes], [have_gsl=no])])
+AM_CONDITIONAL([HAVE_GSL], [test x"$have_gsl" = x"yes"])