Section selectors.
Variable (j: juicy_mem).
Definition m_dry := match j with mkJuicyMem m _ _ _ _ _ => m end.
Definition m_phi := match j with mkJuicyMem _ phi _ _ _ _ => phi end.

Lemma writable_join_sub: forall loc phi1 phi2,
join_sub phi1 phi2 -> writable loc phi1 -> writable loc phi2.