% Source: http://bibiserv.techfak.uni-bielefeld.de/cgi-bin/talp_submit/examples
% From: M. R. K. Krishna Rao, D. Kapur, and R. K. Shyamasundar.
% A transformational methodology for proving termination of logic programs.
% The Journal of Logic Programming, 34:1-41, 1998.

p(a,b).
p(b,c).

tc(X,Y) :- p(Y,Z), tc(X,Z).

% p(c,d).
% p(d,e).
% p(e,f).