proposition: Lemma Rint_reverse_2 : forall f a b x, Rint f a b x -> Rint f b a (-x).
proof: Proof. intros f a b x [pr H]. pose proof RiemannInt_P1 pr as pr2; exists pr2; assert(RiemannInt pr2 = - RiemannInt pr) as Hrew; [ apply RiemannInt_P8 | rewrite Hrew]; rewrite H; intuition. Qed.
imports: Reals RiemannInt RIneq Lra R_sqr MyRfunctions