The exchange went smoothly. From the Red Robe Middle-aged Man's tone, the Immortal Pavilion had offered him the kind of fair price reserved for a longtime honored guest.
Even so, to acquire Immortal Crane Grass, Xichanzi, and the Kunyu Zun, Xu Yi had emptied his pouch of several million spirit stones, along with every last spirit stone he had looted.
After the exchange was complete, the Scarlet Robe Middle-aged Man summoned his adopted son once more—the Green Robe Youth—and instructed him to handle Xu Yi's reception from start to finish.
Xu Yi stayed at Ask Immortal Pavilion for another two days. During that time, he buried himself in books and studied the classics of number theory. The more he explored, the more engrossed he became.
Works like Three Numbers Investigate Doubt and Infinite Numbers fascinated him so deeply that he studied them without pause. He even summoned the Green Robe Youth and had him purchase a large collection of mathematical classics on his behalf, beginning a systematic study of this world's number theory.
He even had the Green Robe Youth take him to meet several renowned number theorists. Unfortunately, his first attempt left him deeply disappointed.
The knowledge possessed by those so-called masters of number theory seemed far too superficial to him.
He suddenly recalled something Elder Bai had once sighed: "How could a true master of number theory be an ordinary person? How could one so easily be found amid the mundane world?"
Now that he turned the words over in his mind, Xu Yi understood them all the more deeply. The wonders of number theory were truly extraordinary.
He revisited the techniques he had studied in the past and found that many of their principles, if threaded through with number theory, could be expressed more simply and concisely,