Axiom hp : Set. Axiom cont : nat -> hp -> Prop. Axiom sconj : (hp -> Prop) -> (hp -> Prop) -> hp -> Prop. Axiom sconjImpl : forall h A B, (sconj A B) h -> forall (A' B': hp -> Prop), (forall h', A h' -> A' h') -> (forall h', B h' -> B' h') -> (sconj A' B') h. Definition cont' (h:hp) := exists y, cont y h. Lemma foo : forall h x y A, (sconj (cont x) (sconj (cont y) A)) h -> (sconj cont' (sconj cont' A)) h. Proof. intros h x y A H. eapply sconjImpl. 2:intros h' Hp'; econstructor; apply Hp'. 2:intros h' Hp'; eapply sconjImpl. 3:intros h'' Hp''; econstructor; apply Hp''. 3:intros h'' Hp''; apply Hp''. 2:apply Hp'. clear H. Admitted.