#include <order/interpreter.h>

#define ORDER_PP_DEF_8ack ORDER_PP_FN(    \
8fn(8X, 8Y,                               \
    8cond((8is_0(8X), 8inc(8Y))           \
          (8is_0(8Y), 8ack(8dec(8X), 1))  \
          (8else, 8ack(8dec(8X), 8ack(8X, 8dec(8Y)))))))

ORDER_PP(8to_lit(8ack(3, 4)))      // 125