English
For p ≠ 0, i arbitrary, sMod(p,i) is nonnegative as an integer.
Русский
Для p ≠ 0 и произвольного i, sMod(p,i) неотрицательно как целое.
LaTeX
$$0 \le sMod(p,i) \quad(\text{при } p \neq 0)$$
Lean4
/-- `q` is defined as the minimum factor of `mersenne p`, bundled as an `ℕ+`. -/
def q (p : ℕ) : ℕ+ :=
⟨Nat.minFac (mersenne p), Nat.minFac_pos (mersenne p)⟩
-- It would be nice to define this as (ℤ/qℤ)[x] / (x^2 - 3),
-- obtaining the ring structure for free,
-- but that seems to be more trouble than it's worth;
-- if it were easy to make the definition,
-- cardinality calculations would be somewhat more involved, too.