On Research: incremental semantics

The purpose of the UNU-IIST Research Day (28-ii-2008) was for us to tell each other about our research: the ideas behind it, why they are important and where they are leading. The ‘metascience’ was as important as the science and provided UNU-IIST fellows with the opportunity to be trained in that aspect of the management of research. Judging by the amount of discussion it provoked, the day was a success. This paper is an elaboration of the talk given by the author, providing more detail than it was possible to give in the talk, but which is necessary if the reader is to evaluate the case being made. The paper makes the case for the incremental approach to program semantics using Galois connections. It considers a sustained case study, that of sequential programs and their related (specification) commands, with the final addition of probabilistic choice. ‘Structural’ decisions are discussed throughout and the conclusion reflects on several issues that arose from the day. Jeff Sanders is Principal Research Fellow at UNU-IIST. His interests lie largely in Formal Methods. Copyright c © 2008 by UNU-IIST