Offline testing.
abstract value. A value whose only operation is equality. Abstract values can be
used to eliminate isomorphic states. NModel considers term labels for object IDs to
be abstract values.
abstraction. Considering certain details and ignoring the rest. Choosing a level of
abstraction. We distinguish data abstraction, behavioral abstraction, and environmental
abstraction.
abstraction function. State property.
accepting state. A state where a run is allowed to stop. Usually, accepting states
are chosen where some goal has been reached or some work has been completed.
accepting state condition. A predicate that defines accepting states.
315
316 Glossary
action. The smallest unit of behavior at the chosen level of abstraction. A discrete,
discontinuous, atomic execution step. Executing an action causes a state transition.
In a reactive system, we distinguish controllable actions from observable actions.
In a model program, the actions are invocations of action methods. In the NModel
framework, actions are represented by terms.
action method. A method in a model program that is associated with an action.
Contrast to helper method.
action symbol. The name of an action. The action symbol is often the same as the
name of the corresponding action method, but not always.
action vocabulary. The collection of action symbols used by a model program.
Pages:
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404