No material object can be completely unbound -say, not connected to anything-. This reified property is defined as not connected to anything which it rigidly depends on.
(<=> (*Unbound-Structure ?Self)
(And (Not (Exists (?Y)
(And (Material-Object ?Y)
(Connected ?Self ?Y)
(Strictly-Depends-On ?Self ?Y))))
(Material-Object ?Self)))