def subsystem ( s ) : node_states ( s . state ) cut ( s . cut , s . cut_indices ) if config . VALIDATE_SUBSYSTEM_STATES : state_reachable ( s ) return True
write a python function to determine if is valid cut
Validate a |Subsystem| .
def subsystem(s):
    """Validate a |Subsystem|.

    Checks its state and cut.
    """
    node_states(s.state)
    cut(s.cut, s.cut_indices)
    if config.VALIDATE_SUBSYSTEM_STATES:
        state_reachable(s)
    return True