Module KI := KSAI'.KI.Module KSAI := KSAI'.Module K := K'.Module KL := KL'.Instance Join_nat_F: Join (nat * F predicate) :=
       Join_prod nat  (Join_equiv nat) (F predicate) _.Instance Perm_nat_F : Perm_alg (nat * F predicate) :=
      @Perm_prod nat _ _ _ (Perm_equiv _) (Perm_F _).Instance Sep_nat_F: Sep_alg (nat * F predicate) :=
      @Sep_prod nat _ _ _ (Sep_equiv _) (Sep_F predicate).

(* Specifications: *)
Lemma unsquash_squash_join_hom : join_hom (unsquash oo squash).