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_app : forall  A eval l1 l2, @make_conj A eval (l1 ++ l2) <-> @make_conj A eval l1 /\ @make_conj A eval l2.
Infix "+++" := rev_append (right associativity, at level 60) : list_scope.