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.

(* Specifications: *)
Theorem make_conj_cons : forall (A : Type) (eval : A -> Prop) (a : A) (l : list A),
make_conj eval (a :: l) <-> eval a /\ make_conj eval l.
Lemma make_conj_impl : forall (A : Type) (eval : A -> Prop) (l : list A) (g : Prop),
(make_conj eval l -> g) <-> make_impl eval l g.
Lemma make_conj_in : forall (A : Type) (eval : A -> Prop) (l : list A),
make_conj eval l -> (forall p, In p l -> eval p).
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.
Lemma make_conj_rapp : forall  A eval l1 l2, @make_conj A eval (l1 +++ l2) <-> @make_conj A eval (l1++l2).
Lemma not_make_conj_cons : forall (A:Type) (t:A) a eval  (no_middle_eval : (eval t) \/ ~ (eval  t)),
~ make_conj  eval (t ::a) <-> ~  (eval t) \/ (~ make_conj  eval a).
Lemma not_make_conj_app : forall (A:Type) (t:list A) a eval
(no_middle_eval : forall d, eval d \/ ~ eval d) ,
~ make_conj  eval (t ++ a) <-> (~ make_conj  eval t) \/ (~ make_conj eval a).