zkevm-docs/8-arithmetic.markdown

@@ -150,8 +150,8 @@ a * b + c = d
 - define t3 = a0 \* b3 + a3 \* b0 + a2 \* b1 + a1 \* b2 (192- 322bit)
 - define t_lo=t0+(t1)\*2^64
 - define t_hi=(t2)+(t3)\*2^64
-- define carry_lo = (t0 + (t1 << 64) + c_lo).saturating_sub(d_lo) >> 128   c_lo is 0
-- define carry_hi = (t2 + (t3 << 64) + c_hi + carry_lo).saturating_sub(d_hi) >> 128 c_hi is 0
+- define carry_lo = (t0 + (t1 << 64) - c_lo) >> 128
+- define carry_hi = (t2 + (t3 << 64) + carry_lo - c_hi) >> 128
 - 如果是 0 行，约束 num_row is 6,并且约束 cnt 自增的有效性
 - a_lo = u16 sum(rotation cur)
 - a_hi = u16 sum(rotation -1)