% From the book % PROLOG PROGRAMMING IN DEPTH % by Michael A. Covington, Donald Nute, and Andre Vellino % (Prentice Hall, 1997). % Copyright 1997 Prentice-Hall, Inc. % For educational use only % WRITELN.PL writeline([]) :- !. writeline([First|Rest]) :- !, write(First), nl, writeln(Rest). writeline(String) :- write(String), nl.