rw [← even_iff_two_dvd]
q s : ℤ
h3_ndvd_q : ¬3 ∣ q
hspos : s ≠ 0
hcoprime' : IsCoprime s q
hodd' : Even q ↔ ¬Even s
⊢ ¬2 ∣ q ^ 2 + 3 * s ^ 2
q s : ℤ
h3_ndvd_q : ¬3 ∣ q
hspos : s ≠ 0
hcoprime' : IsCoprime s q
hodd' : Even q ↔ ¬Even s
⊢ ¬Even (q ^ 2 + 3 * s ^ 2)