Main Function
F_main()
is
 v_T tab%rowtype;
begin
 update table_r set isvalid=f_getvalidvalue(v_t,Score);
 commit;
end;

Sub Function
function F_GetValidValue(p_t in tab%rowtype,p_score in number) return int
is
begin
  ......
   --return somthing here
end;

function f_main return int
is
  i int;
  v_T tab%rowtype;--Is this right?
  --if declare a variable like that the following statement will
  --throw errors.
begin
  F_GetValidValue(V_T); --will throw errors.
end;

function F_GetValidValue(p_t in tab%rowtype) return int
is
begin
  ..
end;

SQL> create or replace package pkg is
  2    function f_main return int;
  3    function f_sub (v_t t%rowtype) return int;
  4  end;
  5  /

Package created.

SQL> create or replace package body pkg is
  2    function f_main return int is
  3      v_t t%rowtype;
  4    begin 
  5      return f_sub (v_t);
  6    end;
  7    function f_sub (v_t t%rowtype) return int is
  8    begin return 1; end;
  9  end;
 10  /

Package body created.

SQL> select pkg.f_main from dual;
    F_MAIN
----------
         1

1 row selected.

Create table tab_t(id int unique not null);
  update tab_t set id=f_sub(vt);

Create table tab_T(id int);

create or replace package pkg_test is
 Function F_main return int;
 Function F_sub(p_t in tab%rowtype) return int;

end pkg_test;
create or replace package body pkg_test is
Function F_main return int
is
  v_t tab%rowtype;
begin
  update tab_t set id=to_char(f_sub(v_t));
  return 100;
  --return f_sub(v_t);  --this will work fine.
end;
Function F_sub(p_t in tab%rowtype) return int
is
begin
  return 100;
end;
end pkg_test;

SQL> create or replace package body pkg_test is
  2  Function F_main return int
  3  is
  4    v_t tab_t%rowtype;
  5    v_id int;
  6  begin
  7    v_id := f_sub(v_t);
  8    update tab_t set id=to_char(v_id);
  9    return 100;
 10    --return f_sub(v_t);  --this will work fine.
 11  end;
 12  Function F_sub(p_t in tab_t%rowtype) return int
 13  is
 14  begin
 15    return 100;
 16  end;
 17  end pkg_test;
 18  /

Package body created.