@techreport{R-87-07,
TITLE = {A Formal Approach to Reason-Maintenance based on Abstract Domains},
AUTHOR = {Peter Haneclou},
YEAR = {1987},
NUMBER = {R-87-07},
INSTITUTION = ida,
ADDRESS = idaaddr,
ABSTRACTURL = {/publications/cgi-bin/tr-fetch.pl?r-87-07+abstr},
ABSTRACT = {Recently the need for a more formal treatment of reason-maintenance has become obvious. Current systems are often ad hoc and most of them only apply to toy-world problems. This paper presents an approach that gives a strict formalization of reason-maintenance. Our approach is similar to the approach taken in denotational semantics (Scott domains).A strict formalization gives one a firm ground to stand on when designing a reason-maintenance system, while also giving the means to determine properties about the system without actually having to build it first.Our abstract domain is a lattice of information states called valuations. valuations are mappings from formulae to truth-values. In order to treat incomplete and inconsistent information we assume an extended set of truth-values. Besides true and false we have the truth-values undefined, meaning lack of information and contradiction, meaning inconsistent information. Sets of inference rules are represented as relations over the set of valuations. The work of a reason-maintenance system is then characterized in terms of operations on the set of valuations.},
IDANR = {LiTH-IDA-R-87-07}