:- [acyl].
:- include('tcyl-24-24-2').

:- table sg/2.

test :- statistics, sg(1,_F), fail.
test :- statistics.

tw :- sg(1,F), write(sg(1,F)), nl, fail.
tw.

sg(X,Y) :- cyl(X,X1), sg(X1,Y1), acyl(Y1,Y).
sg(X,X).