+void
+ttt_board_init (ttt_board_t *board);
+
+void
+ttt_board_init_from_string (ttt_board_t *board,
+ const char *s);
+
+char *
+ttt_board_to_string (ttt_board_t *board);
+
+void
+ttt_board_write (ttt_board_t *board, FILE *file);
+
+ttt_error_t
+ttt_board_make_move (ttt_board_t *board, int move);
+