Incompleteness of relational simulations in the blocking paradigm

Refinement is the notion of development between formal specifications For specifications given in a relational formalism downward and upward simulations are the standard method to verify that a refinement holds their usefulness based upon their soundness and joint completeness This is known to be true for total relational specifications and has been claimed to hold for partial relational specifications in both the non-blocking and blocking interpretations In this paper we show that downward and upward simulations in the blocking interpretation where domains are guards are not Jointly complete This contradicts earlier claims in the literature We illustrate this with an example (based on one recently constructed by Reeves and Streader) and then construct a proof to show why Joint completeness fails in general (C) 2010 Elsevier B V All rights reserve

Failure-Divergence Semantics as a Formal Basis for an Object-Oriented Integrated Formal Method. volume 71

The integration of several different modelling techniques into a single formal method has turned out to be advantageous in the formal design of software systems. Giving a semantics to an integrated formal method is currently a very active area of research. In this paper we discuss the advantages of a failure-divergence semantics for data and process integrating formal methods, in particular for those with a concept of inheritance. The discussion proceeds along the lines of the formal method CSP-OZ, a combination of CSP and Object-Z, developed in Oldenburg.