Sum-set/product construction starting from the 9-point N=125 record and the 8-point N=120 record. In mixed-radix form A=A_125+125 A_120 inside Z/(125*120)Z. Reduction of a+3b=2c+2d modulo 125 first forces equality of the low digits, and after cancellation/division by 125 the N=120 witness forces equality of the high digits. Hence the 9*8=72-element product is valid.
Yongxi (Aaron) Lin · 2026-08-07 22:22:08 UTC