SubQueries in the FROM Clause of SELECT

Consider the following classic query, which counts the number of awards accepted or rejected by employees. It does an outer join to take care of employees who might have only accepted or only rejected awards. This will give one row per employee in an emp_status table:

 select a.id, nvl(accepted, 0)  TotAccepted, 
nvl(rejected, 0) TotRejected,
fname
from emp_status  a, (select count(*) accepted, id,  
code , status
               from  emp_status
               where code  = 'AWARD' 
               and status = 'A'
               group by id, code, status ) b ,
               (select count(*) rejected, id,  
code , status
               from   emp_status 
               where code = 'AWARD'
               and status = 'R'
               group by id, code, status) c ,
               (select id, fname
               from employee) d
where a. code = 'AWARD'
and a.status in ('R', 'A')
and a.id = b.id(+)
and a.id = c.id(+)
and a.id = d.id
group by a.id, accepted, rejected, fname