proposition: Lemma continuity_pt_const : forall f z, constant f -> continuity_pt f z.
proof: Proof. intros ; exists 1%R ; split ; [apply Rlt_0_1 | intros]. rewrite H with x z ; simpl. rewrite C_dist_eq ; trivial. Qed.
imports: Cfunctions Cprop_base Cbase Canalysis_def