cases' Int.four_dvd_add_or_sub_of_odd hre him with h4 h4
case inr.intro
a : ℤ√(-3)
heven : Even (Zsqrtd.norm a)
hre : Odd a.re
him : Odd a.im
⊢ ∃ b, Zsqrtd.norm a = 4 * Zsqrtd.norm b
case inr.intro.inl
a : ℤ√(-3)
heven : Even (Zsqrtd.norm a)
hre : Odd a.re
him : Odd a.im
h4 : 4 ∣ a.re + a.im
⊢ ∃ b, Zsqrtd.norm a = 4 * Zsqrtd.norm b

case inr.intro.inr
a : ℤ√(-3)
heven : Even (Zsqrtd.norm a)
hre : Odd a.re
him : Odd a.im
h4 : 4 ∣ a.re - a.im
⊢ ∃ b, Zsqrtd.norm a = 4 * Zsqrtd.norm b