def weekend_integration_1_SS_idx_rule(M):
    """
    The index for type 1 weekend-tour type integration constraints is
    (day, week, window, tour type).

    :param M: Model
    :return: Constraint index rule
    """

    return [(j, w, i, t) for j in M.DAYS
            for w in M.WEEKS
            for i in M.WINDOWS
            for t in M.activeTT
            if j in M.weekend[i, t]
            and 1 in M.weekend[i, t]
            and 7 in M.weekend[i, t]
            and (i, t, j) in M.okTourTypeDay]