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A state resource is similar to an action resource. It does not manage actively planned actions, but rather the development of a specific property of the environment or the agent itself. For example, an Own Peanut state resource with a Boolean assignment for any one time can provide information about the possession of a peanut (see figure below).

The status of the state resources can restrict the applicability of actions. To execute the action Eat Peanut, it is first necessary to have a peanut. These relations are checked by precondition tasks of actions. A precondition task includes a state value (or value ranges) that must correspond with the state of a related state resource at a specific time.

The effects of actions are more complicated to realize, as multiple actions and events may have synergistic effects. For example, a state resource Hunger with assignments of natural numbers can be influenced by a beneficial action Eat Peanut and a detrimental Walk at the same time.

It is the job of state tasks to describe an action's effects. For instance, a state task of the action Eat Peanut is responsible for a decreasing contribution of -3 to the state resource Hunger during the action's execution (see figure below). Each state resource has a specific state mapping that maps the contributions of the state tasks to values of the state resource's domain. In the case of the Hunger resource, the synergistic effect is a simple addition of the state tasks' single gradients.

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Last update:
May 20, 2001 by Alexander Nareyek