is a person lying in coma living or non living?
Coma is a state of unconsciousness for long periods of time ranging from few hours to many years. During this the person is unable to respond to various stimuli and cannot perform any actions, but the person is living. In many cases, the heart and other body systems are working but due to brain injury or brain damage, the person goes into the state of coma.
Those who are on life support and considered to be brain dead are still living and require nourishment and maintenance. Many years ago I cared for a patient who had been determined to be brain dead. After her parents finally made the painful decision to remove life support, she began to breathe on her own. The "vegetable" that she was anticipated to be was not the case. She recovered, slowly and with a great deal of therapy, and lives a productive life. I guess we are alive until we are dead, and can't assume anything in between.