caa a22 4500 475800117 CHVBK 20180406123735.0 cr unu---uuuuu 170329e20000701xx s 000 0 eng 10.1023/A:1008308620177 doi (NATIONALLICENCE)springer-10.1023/A:1008308620177 Infobase Change: A First Approximation [Elektronische Daten] [Thomas Meyer, Willem Labuschagne, Johannes Heidema] Generalisations of theory change involving operations on arbitrary sets ofwffs instead of on belief sets (i.e., sets closed under a consequencerelation), have become known as base change. In one view, a base should bethought of as providing more structure to its generated belief set, whichmeans that it can be employed to determine the theory contraction operationassociated with a base contraction operation. In this paper we follow suchan approach as the first step in defining infobase change. We think of an infobase as a finite set of wffs consisting of independently obtainedbits of information. Taking AGM theory change (Alchourrón et al. 1985) as the general framework, we present a method that uses the structure of aninfobase B to obtain an AGM theory contraction operation for contractingthe belief set Cn(B). Both the infobase and the obtained theory contraction operation then play a role in constructing a unique infobasecontraction operation. Infobase revision is defined in terms of an analogueof the Levi Identity, and it is shown that the associated theory revisionoperation satisfies the AGM postulates for revision. Because every infobaseis associated with a unique infobase contraction and revision operation, the method also allows for iterated base change. Kluwer Academic Publishers, 2000 base change nationallicence base contraction nationallicence base revision nationallicence belief contraction nationallicence belief revision nationallicence iterated base change nationallicence theory change nationallicence Meyer Thomas Department of Computer Science, University of Pretoria, 0002, Pretoria, South Africa aut Labuschagne Willem Department of Computer Science and Information Systems, University of South Africa, Box 392, 0003, Pretoria, South Africa aut Heidema Johannes Department of Mathematics, Applied Mathematics and Astronomy, University of South Africa, Box 392, 0003, Pretoria, South Africa aut Journal of Logic, Language and Information Kluwer Academic Publishers 9/3(2000-07-01), 353-377 0925-8531 9:3<353 2000 9 10849 https://doi.org/10.1023/A:1008308620177 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1008308620177 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Meyer Thomas Department of Computer Science, University of Pretoria, 0002, Pretoria, South Africa aut NATIONALLICENCE 700 1- Labuschagne Willem Department of Computer Science and Information Systems, University of South Africa, Box 392, 0003, Pretoria, South Africa aut NATIONALLICENCE 700 1- Heidema Johannes Department of Mathematics, Applied Mathematics and Astronomy, University of South Africa, Box 392, 0003, Pretoria, South Africa aut NATIONALLICENCE 773 0- Journal of Logic, Language and Information Kluwer Academic Publishers 9/3(2000-07-01), 353-377 0925-8531 9:3<353 2000 9 10849 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer