[jarnold30]

hi, is there any way, given 2 lists or sets, to check if one is a subset of the other?

[Harrison Pratt]

Classical way, easy to understand:

Code: Select all

class predicates
    isSubSet : (T* CheckTerms, T* Terms) determ.
clauses
    isSubset([H], Terms) :-
        list::isMember(H, Terms),
        !.
    isSubset([H | TT], Terms) :-
        list::isMember(H, Terms),
        isSubSet(TT, Terms).

Another way using VIP list class predicates. Put your cursor on "list::all" in your code and press F1 for more information.

Code: Select all

        % ... some code ...
        L1 = [1, 2, 3, 4, 5, 6],
        L2 = [0, 3, 4, 5, 5],
        list::all(L2, { (E) :- list::isMember(E, L1) }), % will FAIL because 0 is not a member of L2
        % ... some more code ...

You may need to do some reading on list domains here: https://wiki.visual-prolog.com/index.ph ... st_Domains

[jarnold30]

thanks