fact: Fixpoint eval n m (x: expr n m): X (f' n) (f' m) := match x with | e_zer _ _ => 0 | e_top _ _ => top | e_one _ => 1 | e_pls _ _ x y => eval x + eval y | e_cap _ _ x y => eval x ∩ eval y | e_neg _ _ x => ! eval x | e_dot _ _ _ x y => eval x ⋅ eval y | e_itr _ x => (eval x)^+ | e_str _ x => (eval x)^* | e_cnv _ _ x => (eval x)° | e_ldv _ _ _ x y => eval x -o eval y | e_rdv _ _ _ x y => eval y o- eval x | e_var a => f a end.
imports: positives comparisons Eqdep monoid