Computer Science Homework Help

/* Consider the following Prolog program: */

member(X,[X|Xs]).

member(X,[Y|Xs]) :- member(X,Xs).

disjoint([],Ys).

disjoint([X|Xs], Ys) :- not(member(X, Ys)), disjoint(Xs,Ys).

/*

Draw the derivation trees for the following queries:

(a) ?- disjoint([1,2,3],[4,2]).

(b) ?- disjoint([1,2,3],Xs).

(c) ?- not(not(disjoint(Xs,[4,2]))).

As a short reminder:

+ Goal

is the same as

not(Goal)

*/