permutation([],[]).
permutation([X | Xs],[Z | Zs]) :- select(Z,[X | Xs],Ys),permutation(Ys,Zs).

select(X,[X | Xs],Xs).
select(Y,[X | Xs],[X | Ys]) :- select(Y,Xs,Ys).

anagrammi(X) :- string_to_list(X,L),iterapermutazione(L,P).

iterapermutazione(L,P) :- permutation(L,P),scrivi(P),fail.
iterapermutazione(X,Y).

scrivi(P) :- name(Str,P),writeln(Str),!.