with 
a1 (insert into a1 select ... returns *),
a2 (insert into a2 select ... returns *),
a3 (delete from a2 where returns *),
a4 (delete from a3 where returns *),
a5 (insert into a4 select * from a4 returns *) 
select true;

with 
a1 (insert into tab_a1 select ... returns *),
a2 (insert into tab_a2 select ... returns *),
a3 (delete from tab_a2 where returns *),
a4 (delete from tab_a3 where returns *),
a5 (insert into tab_a4 select * from a4 returns *) 
select true;

with t (
       select 
              exists (select 1 from table1 where id=13) 
              and not exists (select 1 from table2 where id=130) as uslovie
),
a       (insert into dictionary1(id, name) select 100, N'kakaya-to fignya'
        where exists (select uslovie from t)
),
b      (
        update dictionary2 set name=N'bolshaya fignya' where id=101
        where exists (select uslovie from t)
),
c      (
        insert into dictionary2(id, name) select 100, N'kakaya-to bolshaya fignya'
        where not exists (select uslovie from t)
),
d      (  
        update dictionary1 set name=N'malenkaya fignya' where id=100
        where not exists (select uslovie from t)
)
select true