def pl_true_int_repr(clause, model={}):
    """Lightweight version of pl_true.

    Argument clause represents the set of args of an Or clause. This is used
    inside dpll, it is not meant to be used directly.

    >>> pl_true_int_repr({1, 2}, {1: False})
    >>> pl_true_int_repr({1, 2}, {1: False, 2: False})
    False

    """
    result = False
    for lit in clause:
        if lit < 0:
            p = model.get(-lit)
            if p is not None:
                p = not p
        else:
            p = model.get(lit)
        if p is True:
            return True
        elif p is None:
            result = None
    return result
