Acting on a subject system

A logic-based computing device including an actor for effecting action in a subject system, the device comprising:

• means for implementing a model of the subject system, the model including:
• objects which represent objects within the subject system, each object in the model having associated therewith an indication of which of at least one state the object is in at a given time, and
• rules which define actions which are to be initiated in response to events, an event being the change in the state of an object, and
• means for implementing a processor, arranged:
• to respond to an event in the subject system by initiating at least one action in the subject system which is dependent on the event, as defined by the rules of the model.

A method of effecting action in a subject system, the method comprising:

• maintaining a model of the subject system, the model including:
• objects which represent objects within the subject system, each object in the model having associated therewith data which define which of at least two states the object is in at a given time, and
• rules which define actions which are to be initiated in response to events, an event being the change in the state of an object, and
• controlling a processor, to respond to an event in the subject system by initiating at least one action in the subject system which is dependent on the event, as defined by the rules of the model.

A method of effecting action in a subject system, the method comprising:

• maintaining in a logic-based computing device means for implementing a model of the subject system, the model including:
• objects which represent objects within the subject system, each object in the model having associated therewith an indication of which of at least two states the object is in at a given time, and
• rules which define actions which are to be initiated in response to events, an event being the change in the state of an object;
• and
• maintaining in the logic-based computing device means for implementing a processor, and controlling the processor to respond to an event in the subject system by initiating at least one action in the subject system which is dependent on the event, as defined by the rules of the model.

A method of controlling a complier to use one of a) a model of a Von Neumann-like computer, b) a model of an operating system which manages the resources of a Von Neumann-like computer and c) a model of an operating system which provides a simpler interface to a Von Neumann-like computer, to translate statically an application model comprising:

• objects which represent objects in the application, each object in the application model having associated therewith data which define which of at least one state the object is in at a given time;
• and
• rules which define actions which are to be initiated in response to events, an event being the change in the state of an object,
• into one of A) the object of a Von Neumann-like computer, B) machine code of a Von Neumann-like computer, C) assembler code of a Von Neumann-like computer, D) an operating system which manages the resources of a Von Neumann-like computer and E) an operating system which provides a simpler interface to a Von Neumann-like computer, for acting on a subject system.

A method of modelling a subject system comprising:

• maintaining a model of the subject system, the model including:
• objects which represent objects within the subject system, each object in the model having associated therewith data which define which of at least one state the object is in at a given time;
• rules which define actions which are to be initiated in response to events, an event being the change in the state of an object;
• and
• rules which define a composite action initiated in response to an event in terms of sub-actions each of which is initiated in response to events one of a) directly and b) indirectly resulting from the execution of the composite action