Add Ring GeometricRing : ringF.Add Field GeometricField : fieldF.Global Instance Fops: (@Ring_ops F OF OneF AddF MulF SubF OppF EqF) := {}.Global Instance FRing : (Ring (Ro:=Fops)).Global Instance Fcri: (Cring (Rr:=FRing)).Notation "0" := OF : FScope.Notation "1" := OneF : FScope.Notation "2" := TwoF : FScope.Infix "+" := AddF : FScope.Infix "*" := MulF : FScope.Infix "-" := SubF : FScope.Notation "- x" := (OppF x) : FScope.Infix "/" := DivF : FScope.Infix "<=" := LeF : FScope.Infix "=F=" := EqF (at level 70) : FScope.

Lemma Fmult_integral : forall A B, A * B =F= 0 -> A =F= 0 \/ B =F= 0.