diff --git a/src/brchess.h-move-to-temp-migration-bitboard__brchess.h b/src/brchess.h-move-to-temp-migration-bitboard__brchess.h
new file mode 100644
index 0000000..e8863d3
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+++ b/src/brchess.h-move-to-temp-migration-bitboard__brchess.h
@@ -0,0 +1,21 @@
+/* brchess.h - main loop.
+ *
+ * Copyright (C) 2021-2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef BRCHESS_H
+#define BRCHESS_H
+
+#include "position.h"
+
+int brchess(pos_t *pos);
+
+#endif  /* BRCHESS_H */