Definition Q_eq_dec : forall x y : Q, {x = y} + {x <> y}.

Theorem Q_distr_left_aux : forall (x y : Q) (z' : Qpositive), Qmult (Qplus x y) (Qpos z') = Qplus (Qmult x (Qpos z')) (Qmult y (Qpos z')).