Fixpoint make_conj (A : Type) (eval : A -> Prop) (l : list A) {struct l} : Prop :=
match l with
| nil => True
| cons e nil => (eval e)
| cons e l2 => ((eval e) /\ (make_conj eval l2))
end.

Lemma make_conj_rapp : forall  A eval l1 l2, @make_conj A eval (l1 +++ l2) <-> @make_conj A eval (l1++l2).