proposition: Lemma integral_inv : forall H, Integral ( {--}F) H [=] [--] (Integral F contF).
proof: Proof. intro. assert (H0 : Continuous_I Hab ([0]{**}F{+}[--][1]{**}F)). Contin. apply eq_transitive_unfolded with (Integral _ H0). apply integral_wd; FEQ. eapply eq_transitive_unfolded. apply linear_integral with (contF := contF) (contG := contF). rational. Qed.
imports: CoRN.ftc.RefLemma Coq(Lia)