function CF_2Formula return Number is
yopn number(10,2);
yrec number(10,2);
mqty number(10,2);
total number(10,2);
PR_NOT_FOUND EXCEPTION;
begin
  --- opening balance from yarn table
  Select sub1.opn, sub2.RecKGS, sub3.rmqty  into yopn,yrec,Mqty from 
   (select y.yarn_type, y.balance Opn from yarn y) sub1,
   
 (select yr.yarn_type yarnType, sum(yr.rec_kgs) RecKGS
 from sub_yarn_received yr group by yr.yarn_Type) sub2,
 
 (select p.ppno ppno, p.subpp subpp, p.req_date ETD, p.fabric_code, sum(s.req_kgs) RmQTY, p.b_code
  from  program p, sub_program s 
  where s.jobno = p.jobno  
  and req_date not between :dd and :dd1
  group by p.ppno, p.subpp, p.b_code, p.fabric_code, req_date) sub3,

(select l.fabric_code fabric_code, sl.yarn_code yarn_code, sl.cons cons
from link l, sub_link sl
where sl.jobno= l.jobno
group by l.fabric_code, sl.yarn_code, sl.cons) sub5,

(select y.yarn_code, y.yarn_type yarn from yarn y) sub6,
 
(select b.b_code, b.b_ref 
from buyer b) sub4
where sub3.b_code = sub4.b_code 
and sub5.fabric_code = sub3.fabric_code
and sub5.yarn_code=sub6.yarn_code
and sub6.yarn = :yarn
and sub2.yarnType = :yarn
and sub1.yarn_type = :yarn;

IF SQL%NOTFOUND THEN 
			RAISE PR_NOT_FOUND;
     	END IF;
     		EXCEPTION 
			WHEN PR_NOT_FOUND THEN
			null;
			
     total:= yopn+yrec+mqty;
    
     return(total);
     
     	
end;

BEGIN
  SELECT column_list INTO variables
  FROM (SELECT ... ) sub1,
       (SELECT ... ) sub2,
       ...
  WHERE conditions;

EXCEPTION
  WHEN NO_DATA_FOUND THEN
    deal with it;
END;