Glossary

• Commitment strategy (refinement strategy)- automatically decides next refinement operations.
• Compound task - a task which can be accomplished by a series of primitive tasks.
• Constraint - conditions associated with a task-network. There are three constraint types; variable constraints, ordering constraints and state constraints.
• Constraint posting - Constraints which can not be fully enforced at the time of enforcement will be posted in the promissory list.
• Constraint refinement - Same as constraint enforcement. Enforcing the constraint by making necessary changes in the task-network data structure.
• Constraint simplification - simplifying the constraint formula attached to the current task-network by evaluating each constraint and replacing already satisfied constraints with T and
• Critics (user critics) - User mechanism to guide and prune the search.
• Effect - a change in the state of the world as a result of executing a primitive task. An effect is specified by a literal. A negative literal means deleting it from the state if exists.
• Expansion - task expansion. Decomposion of a non-primitive task using its methods.
• Goal - goal task-network.
• Initial state - the state before any execution of tasks. It is a list of atoms which hold true in the initial state.
• Method - a task-network describing how to achieve the non-primitive task.
• Dummy method - when a predicate is expanded, its first method used is this method of assuming the predicate is true without doing any specific operation.
• Operator - a primitive task.
• Postcondition - an effect of the primitive task.
• Precondition - a condition necessary to be satisfied to execute the primitive task.
• Predicate task - a task which is also a state predicate. It may be accomplished without doing anything.
• Primitive task (operator) - a task (action) which can be executed. (see Dummy method)
• Refinement - a choice of works to be done to generate a valid plan.
• Task-network - a partially ordered tasks with constraints and data-structures attached to them.
• Primitive task-network - a task-network whose tasks are all predicate tasks.

Go back to Main Page

Web Accessibility