Specifying fault tolerant programs in deontic logic
Jaa Jos Coenen · TU/e Research Portal · 1991
Fault tolerant systems are, like most complex systems, structured in layers.In a fault tolerant layered system, a malfunction on a lower level layer occurs at a higher level as an imperfection, that may prohibit the upper layer from exhibiting its preferred behaviour.The behaviour of a system in such less than perfect circumstances should not be left unspecified.Deontic logic offers the possibility to specify layered fault tolerant systems in a natural way.More specifically, dyadic modalities are used to specify the preferred behaviors of a fault tolerant system in different conditions.The use of dyadic rather than monadic modalities is also discussed in the context of a particular problem that arises when specifying fault tolerant systems and which is referred to as the 'lazy programmer' paradox.The 'lazy programmer' paradox is illustrated by a few 'toy' examples.The application of deontic logic as a specification language for fault tolerant systems is illustrated by the specification of a nOD-trivial example.