Swifterbant S4 (the Netherlands):Occupation and exploitation of a Neolithic levee site (c. 4300-4000 cal. BC)

This publication presents the results of the 2005-2007 excavations at Swifterbant S4, carried out by the Groningen INstitute of Archaeology. S4 is a well-preserved Neolthic wetland site (c. 4300-4000 cal. BC) located within the Swifterbant river system in the Netherlands. We present the landscape setting, the various find categories and the spatial patterns with three research themes in mind. Theme 1 concerns the environmental setting, subsistence and site function. We conclude that the Swifterbant hunter-gatherer-farmers exploited a mosaic-type landscape. Theme 2 deals with developments in site function during the exploitation and exploitation history of the site. This analysis leads to the observation that episodes of cultivation and settlement alternated at S4. Theme 3, the use of space, was difficult to study due to the fragmented nature of the excavation plan. This site monograph makes Swifterbant S4 the most comprehensively published site of the Swifterbant river system

Composition mechanisms for retrenchment

Retrenchment is a flexible model evolution formalism that arose as a reaction to the limitations imposed by refinement, and for which the proof obligations feature additional predicates for accommodating design data. Composition mechanisms for retrenchment are studied. Vertical, horizontal, dataflow, parallel and fusion compositions are described. Of particular note are the means by which the additional predicates compose. It is argued that all of the compositions introduced are associative, and that they are mutually coherent. Composition of retrenchment with refinement, so important for the smooth interworking of the two techniques, is discussed. Decomposition, allowing finer grained retrenchments to be extracted from a single large grained retrenchment, is also investigated

A robust semantics hides fewer errors

In this paper we explore how formal models are interpreted and to what degree meaning is captured in the formal semantics and to what degree it remains in the informal interpretation of the semantics. By applying a robust approach to the definition of refinement and semantics, favoured by the event-based community, to state-based theory we are able to move some aspects from the informal interpretation into the formal semantics