Infix "+++" := rev_append (right associativity, at level 60) : list_scope.

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).