@techreport{R-88-15, TITLE = {LINCKS: An Imperative Object Oriented System}, AUTHOR = {Lin Pagdham and Ralph R{\"o}nnquist }, YEAR = {1988}, NUMBER = {R-88-15}, INSTITUTION = ida, ADDRESS = idaaddr, ABSTRACTURL = {/publications/cgi-bin/tr-fetch.pl?r-88-15+abstr}, ABSTRACT = {We present the LINCKS (Link{\"o}pings Intelligent Knowledge Communication System) system which is under development at Link{\"o}ping University, and the theoretical model on which it is based. LINCKS is an object oriented system in the sense that objects in the real world are represented directly within the system, allowing for a clear and simple mapping from the real world to a computer model of some aspect of the real world. The object oriented model used differs significantly from that used in Smalltalk, Simula, and many other object oriented languages. The most fundamental differences are in the view of typing and the view of actions. A typing schema is regarded as part of the context for a user or a software tool, with many different typing schemas being allowed to co-exist within the system. Actions are not represented as messages and methods attached to objects as in Smalltalk. Instead actions have their own structure and organisation, and include information about their pre and post conditions. This gives the system a more imperative nature than many object oriented systems. A history mechanism is also described which allows recreation of any object as it existed at some previous point in time. The history mechanism also provides information to be used by reasoning software. LINCKS is compared to Smalltalk with respect to some important differences.}, IDANR = {LiTH-IDA-R-88-15}, NOTE = {Also in Proc of the 20th Annual Hawaii Int. Conf. on System Sciences, Hawaii, 1987}