I suppose that stems from a common history and mutual dependency.

The missing cat represents her decision not to close herself off from love and mutual dependency.

In particular, it should consider the lack of investment in managerial employee relations skills and a culture of mutual dependency between unions and industrial relations departments.

As such, their working relationship becomes one of mutual dependency, each watching the other's back when either of them sail too close to the wind.

This constraint on the system as a whole implies a form of mutual dependency or coordination between its subsystems or components.