ERRATA
                             ======
Benchmarks from De Schreye and Decorte:
In dds1.1
append([H|X],Y,[X|Z]) :- append(X,Y,Z).
                ^ should be H
(pointed out by Alexander Serebrenik)


Benchmarks from Pluemer:
 * in pl8.2.1a: clause m5 = merge(X,[],X). is missing

 * in mergesort_t:

   merge([X|Xs],[Y|Ys],[X|Zs]) :- X>Y, merge([X|Xs],Ys,Zs).
                        ^ should be a Y
(pointed out by Claus Claves)

I am grateful for the corrections - did not change the benchmarks because
people have been using them as they are.
                                      N.L.