extern const char ach_turn[2];
extern const unsigned char aifile[ nsquare ];
extern const unsigned char airank[ nsquare ];
+extern int root_pos[]; // [HGM] remembers root position during pondering
extern int move_list[], move_ptr; // [HGM] undo: game history (used in proce.c and makemove.c)
extern char analyze_mode; // [HGM] exclude: used in proce.c and root.c