Prolog Text einstein

 * Prolog code for the Einstein riddle.
 * First published as "Who owns the Zebra?" in the Life International
* magazine on December 17, 1962 with solution given in the March 25,
* 1963 issue. The riddle given here is not a verbatim copy.
* Copyright 2012, XLOG Technologies GmbH, Switzerland * Jekejeke Prolog 0.9.3 (a fast and small prolog interpreter) */ member(X,[X|_]). member(X,[_|Y]) :- member(X,Y). rightTo(L, R, [L,R | _]). rightTo(L, R, [_ | Rest]) :- rightTo(L, R, Rest). nextTo(X, Y, List) :- rightTo(X, Y, List). nextTo(X, Y, List) :- rightTo(Y, X, List). einstein(Houses, FishOwner) :- Houses = [[house,norwegian,_,_,_,_],_,[house,_,_,_,milk,_],_,_], member([house,brit,_,_,_,red], Houses), member([house,swede,dog,_,_,_], Houses), member([house,dane,_,_,tea,_], Houses), rightTo([house,_,_,_,_,green], [house,_,_,_,_,white], Houses), member([house,_,_,_,coffee,green], Houses), member([house,_,bird,pallmall,_,_], Houses), member([house,_,_,dunhill,_,yellow], Houses), nextTo([house,_,_,dunhill,_,_], [house,_,horse,_,_,_], Houses), member([house,_,_,_,milk,_],Houses), nextTo([house,_,_,marlboro,_,_], [house,_,cat,_,_,_], Houses), nextTo([house,_,_,marlboro,_,_], [house,_,_,_,water,_], Houses), member([house,_,_,winfield,beer,_], Houses), member([house,german,_,rothmans,_,_], Houses), nextTo([house,norwegian,_,_,_,_], [house,_,_,_,_,blue], Houses), member([house,FishOwner,fish,_,_,_], Houses). test :- einstein(_,_). * Prolog code for memory monitor.