Maintainability: a weaker stabilizability like notion for
high level control.
Mutsumi Nakamura, Chitta Baral and Marcus Bjareland.
Abstract
The goal of most agents is not just to reach a goal state, but
rather also (or alternatively) to put restrictions on its
trajectory, in terms of states it must avoid and goals that it
must `maintain'. This is analogous to the notions of `safety' and
`stability' in the discrete event systems and temporal logic
community.
In this paper we argue that the notion of `stability' is too
strong for formulating `maintenance' goals of an agent -- in
particular, reactive and {\em software agents}, and give examples
of such agents. We present a weaker notion of `maintainability'
and show that our agents which do not satisfy the stability
criteria, do satisfy the weaker criteria. We give algorithms to
test maintainability, and also to generate control for
maintainability. We then develop the notion of `supportability'
that generalizes both `maintainability' and `stabilizability,
develop an automata theory that distinguishes between exogenous
and control actions, and develop a temporal logic based on it.