Oracle - string combinatorial permutation

Question

I think I have a complex requirement.

It\'s a combinatorial permutation using Oracle 10.2, I\'was able to solve it using cartesian joins, but I think that it need so

Answer 1

Edit: Got the generic one. Really simple in the end (but took me a while to get there)

WITH words AS
(   SELECT  REGEXP_SUBSTR( '&txt', '\S+', 1, LEVEL )    AS word
        ,   LEVEL                                       AS num
    FROM    DUAL
    CONNECT BY LEVEL <= LENGTH( REGEXP_REPLACE( '&txt', '\S+\s*', 'X' ) )
)
SELECT  SYS_CONNECT_BY_PATH( W.word, ' ' )
FROM    words   W
CONNECT BY NOCYCLE PRIOR W.num != W.num

Edit2: Removed redundant maxnum stuff. Left over from previous attempts