oracle - SQL select statement union all with itself -

hi have complicated sql statement returns results.
of results in table same id.
have result set first plus duplicate of rows belong other table.

the code below wrong shows trying achieve:

select myrules.*  (complicated sql statement) myrules union select myrules  inner join table2 on myrules.id =table2.id; 

is possible?

ps1. don't want touch complicated sql statement.
ps2. error myrules table or view not exist

edit: based on answers try create procedure returns cursor got error in line open cursor:

procedure get_rules(in_id      in tablea.reconciliation_id%type,                     io_cursor  in out t_ref_cursor) begin  myrules (  complicated sql statement)  open io_cursor   -- errors here: missing select keyword select *    myrules    union select *    myrules    inner join table2   on myrules.id = table2.id; end get_rules; 

yes, valid union all query query on same table. better use with in case:

with myrules (   complicated sql statement ) select * myrules union select *  myrules  inner join table2 on myrules.id = table2.id; 

if want use with in cursor, embed in cursor, not stored procedure:

procedure get_rules(in_id      in tablea.reconciliation_id%type,                     io_cursor  in out t_ref_cursor) begin   open io_cursor    myrules (    complicated sql statement   )   select *   myrules   union   select *    myrules    inner join table2   on myrules.id = table2.id; end get_rules;