Adapted from the Li₂ light-certificate project and mo271/Zeta5; see NOTICE.
theorem
Zeta32.rational_nonzero_of_constant_reduction
(P : Polynomial ℤ)
(p : ℕ)
[Fact (Nat.Prime p)]
(c : ZMod p)
(hc : c ≠ 0)
(hred : Polynomial.map (Int.castRingHom (ZMod p)) P = Polynomial.C c)
(q : ℚ)
(hb : ↑q.den ≠ 0)
: