proposition: Lemma ex_C_RInt_segm_plus (f g : C -> C) (z1 z2 : C) : ex_C_RInt_segm f z1 z2 -> ex_C_RInt_segm g z1 z2 -> ex_C_RInt_segm (fun z => f z + g z) z1 z2.
proof: Proof. intros (If,Hf) (Ig,Hg). exists (If + Ig). by apply is_C_RInt_segm_plus. Qed.
imports: Coq(Reals ssreflect) Coquelicot(Coquelicot)