Definition Qquadratic :
  Z ->
  Z ->
  Z ->
  Z ->
  forall (e f g h : Z) (s1 s2 : Q)
    (H_Qquadratic_denom_nonzero : Qquadratic_denom_nonzero e f g h s1 s2), Q.

Lemma Qquadratic_denom_nonzero_Zero_Zero_always_Zero : forall (g : Z) (s1 s2 : Q) (H_nonzero_s2 : s2 <> Zero :>Q), g <> 0%Z -> Qquadratic_denom_nonzero 0 0 g 0 s1 s2.