The nub() function removes duplicates from a list

nub.erl

-module (nub).
-export ([nub/1, containsElement/2]).

% Remove duplicates in a list, keeping the order of the last occurences
-spec nub([T]) -> [T].
nub([]) -> [];
nub([X|Xs]) ->
    case containsElement(Xs, X) of
        true -> nub(Xs);
        false -> [X|nub(Xs)]
    end.

% Whether a list contains a particular element
containsElement([], _Elmt) ->
    false;
containsElement([X|Xs], Elmt) ->
    (X == Elmt) orelse containsElement(Xs, Elmt).