. () ().
:
R:- A,U,,R,.
R - , , U - , , ,, - , . ( ).
1.
song:- write(','),song.
:
?- write(' '),song.
, . ("" ).
, , b e - .
, . , .
.
2.
song(X):-(X>1),write(','),(Y is X - 1),song(Y).
song(1).
?-write(' '),song(3),write(' ').
(X > Y) (X is A, X , A - , ).