std::string value(Value v);
std::string square(Square s);
std::string move(Move m, bool chess960);
-std::string pv(const Position& pos, Depth depth, Value alpha, Value beta);
+std::string pv(const Position& pos, Depth depth);
std::string wdl(Value v, int ply);
Move to_move(const Position& pos, std::string& str);