disjoint in prolog 1

[12071982]

Can anyone help me do such routine in prolog
disjoint([1,2,3],[2,3,4],Ans) binds Ans to [1,4]

thnx

 

[joel76]

disjoint(X,Y,R).

If I have understood your question, you just have to write in English what you find in Ans, and translate it in Prolog eg in R, you find elements of X which are not in Y and elements of Y which are not in X.

So, begin by writing a rule that takes 2 lists A and B, and give a list C containing elements of A which are not in B.

 

[12071982]

Can anyone write a prolog routine for me for
disjoint([1,2,3],[2,3,4],Ans) binds Ans to [1,4]
coz though i managed to understand the concept, i dont know how to implement it by programming.
I cant use reserved words found in prolog for my assignment.

thnx
lor

 

[joel76]

Here is the code for "a rule that takes 2 lists A and B, and give a list C containing elements of A which are not in B."

% in_A_but_not_in_B(+LstA, +LstB, +Lst_in_Construction, -Lst_Final)
% when A is finished, we unify Lst_in_Construction and Lst_Final
in_A_but_not_in_B([], _, L, L).


% we check if the first element of A is in B
in_A_but_not_in_B([H|T], B, LC, LF) :-
	member(H, B),
	% yes, it's in, we don't memorize it
	% and we carry on with the rest of liste A
	in_A_but_not_in_B(T, B, LC, LF).

% we check if the first element of A is in B
in_A_but_not_in_B([H|T], B, LC, LF) :-
	\+member(H, B),
	% no, it's not in it, we memorize it
	% and we carry on with the rest of liste A
	in_A_but_not_in_B(T, B, [H| LC], LF).

test(R) :-
	% when we start, List_in_Construction is empty
	in_A_but_not_in_B([1,2,3, 5], [2,3,4], [], R).

 

[12071982]

thanks a lot for your help ..i think i can manage now

 

[12071982]

I managed to do my prolog problem thanks to your help

Thanks once again...much obliged