def set_auto_forward(auto):
    """Set the default mode for automatic forward propagation.

    When it is set to `True` , forward propagation is invoked immediately when the computation graph
    is updated.

    Args:
        auto (bool): Whether forward computation is executed when the
            computation graph is updated.

    Returns: bool
    """
    global __auto_forward_state
    __auto_forward_state = auto
