+#include "language/expressions/helpers.h"
+#include "language/expressions/public.h"
+#include "libpspp/assertion.h"
+#include "libpspp/message.h"
+#include "libpspp/misc.h"
+#include "libpspp/pool.h"
+#include "libpspp/str.h"
+
+#include "gl/xalloc.h"