1%:- statistics( walltime, [X,Y]), XY is X+Y, srandom(X),!.
    2random(X):- X is random.
    3:- use_module(library(random)).    4:- use_module(library(lists)).    5
    6/*flatten([], []).
    7flatten([H|T], M) :- flatten(H, Hf),
    8   flatten(T, Tf),
    9   append(Hf, Tf, M).*/
   10
   11round(X,Y):- Y = round(X)