on_x_rtrace(C):-
   catch(C,E,
     (writeln(E),visible(+all), leash(-all),leash(+exception),C)).


%% File handling code for prolog

save_to_file(File_name, Term) :- %Term should be an instantiated list
    open(File_name, write, Data),
    set_stream(Data,representation_errors(prolog)),
    % set_stream(Data,encoding(utf8)),
    write_results_to_file(Data, Term),
    close(Data).

% write to file stream. Saves only the most recently asserted results.
write_results_to_file(Stream, [H|Rest]) :-
    on_x_rtrace(write(Stream, H)),
    write(Stream, "\n"),
        write_results_to_file(Stream, Rest).

write_results_to_file(Stream, []) :-
    write(Stream, "\n"), !.