[m-dev.] list.all2

[Paul Bone]

Hi Guys.

I've created a predicate list.all2 that succeeds if two lists are equal
and all pairs of elements from each satisfy a predicate.

:- pred list_all2(pred(A, B), list(A), list(B)).
:- mode list_all2(pred(in, in) is semidet, in, in) is semidet.

list_all2(_, [], []).
list_all2(P, [X | Xs], [Y | Ys]) :-
    P(X, Y),
    list_all2(P, Xs, Ys).


Is this useful enough to be added to the standard library?

Thanks.

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