#[global]
Instance Qops: (@Ring_ops Q 0%Q 1%Q Qplus Qmult Qminus Qopp Qeq).#[global]
Instance Qri : (Ring (Ro:=Qops)).#[global]
Instance Qcri: (Cring (Rr:=Qri)).

Lemma Q_one_zero: not (Qeq 1%Q 0%Q).