| 摘要 |
<p>. A computer-controlled system, e.g. a telephone exchange, includes a plurality of interactive resources each of which may take one of a plurality of states wherein the identities of resources directly interacting with a given resource are stored within the given resource. A change of state of the given resource is only permitted when the states of the directly interacting resources are compatible with the change, the resources being arranged in a hierarchy so that the given resource has stored within it the identity of parent resources directly above it in the hierarchy which limit its highest state and also has stored within it the identity of dependent resources directly below it in the hierarchy whose highest states it limits.</p> |
