proposition: Lemma epsilon_sup I J (f: I -> regex'): eps (\sup_(i\in J) f i) ≡ \sup_(i\in J) eps (f i).
proof: Proof. induction J. reflexivity. simpl. fold_regex. now rewrite <-IHJ, orb_pls. Qed.
imports: monoid regex lset boolean sups matrix_ext normalisation