proposition: Lemma ex_C_RInt_segm_opp (f : C -> C) (z1 z2 : C) : ex_C_RInt_segm f z1 z2 -> ex_C_RInt_segm (fun z => - f z) z1 z2.
proof: Proof. intros (If,Hf). exists (- If). by apply is_C_RInt_segm_opp. Qed.
imports: Coq(Reals ssreflect) Coquelicot(Coquelicot)