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

Retrenching the Purse: Finite Exception Logs, and Validating the Small

The Mondex Electronic Purse is an outstanding example of industrial scale formal refinement, and was the first verification to achieve ITSEC level E6 certification. A formal abstract model and a formal concrete model were developed, and a formal refinement was hand-proved between them. Nevertheless, certain requirements issues were set beyond the scope of the formal development, or handled in an unnatural manner. The retrenchment Tower Pattern is used to address one such issue in detail: the finiteness of the purse log (which records unsuccessful transactions). A retrenchment is constructed from the lowest level model of the purse system to a model in which logs are finite, and is then lifted to create two refinement developments of the purse, working at different levels of detail, and connected via retrenchments, forming the tower. The tower development is appropriately validated, vindicating the design used

Between continuity and paradigm shift: Pension reforms in Germany

In general, the policy domain of old-age pensions is characterized by institutional continuity and only incremental reforms. Since the late 1980s, in Germany a series of public pension reforms, all initiated in view of imminent population aging, have happened. In this paper it is looked into the process and content of reforms legislated between 1989 and 2001 in order to understand the nature of change and its driving forces. The main question to be answered is whether these single reform steps eventually amounted to a 'path departure'. Despite the reforms the public pension scheme will continue to be the central component of retirement income for the next decades to come, and traditional features of that social insurance program remained intact. However, it can no longer be regarded as a coherent and undisputed policy paradigm: pension politics has become increasingly conflictuous, and the scope of policy-making has widened from public pension policy (parametric reforms concerning a tighter contribution-benefit link, prolonged working life, adjustment formulae etc.) to retirement income policy. Thereby some of the public scheme's established principles have been abandoned, non-public components of retirement income are pushed and new actors become involved in the politics of pensions. It is thus justified to speak of a paradigmatic change that has occurred. --

Between continuity and paradigm shift: pension reforms in Germany

"In general, the policy domain of old-age pensions is characterized by institutional continuity and only incremental reforms. Since the late 1980s, in Germany a series of public pension reforms, all initiated in view of imminent population aging, have happened. In this paper it is looked into the process and content of reforms legislated between 1989 and 2001 in order to understand the nature of change and its driving forces. The main question to be answered is whether these single reform steps eventually amounted to a 'path departure'. Despite the reforms the public pension scheme will continue to be the central component of retirement income for the next decades to come, and traditional features of that social insurance program remained intact. However, it can no longer be regarded as a coherent and undisputed policy paradigm: pension politics has become increasingly conflictuous, and the scope of policy-making has widened from public pension policy (parametric reforms concerning a tighter contribution-benefit link, prolonged working life, adjustment formulae etc.) to retirement income policy. Thereby some of the public scheme's established principles have been abandoned, non-public components of retirement income are pushed and new actors become involved in the politics of pensions. It is thus justified to speak of a paradigmatic change that has occurred." (author's abstract

Tactics From Proofs

Proof guarantees the correctness of a formal specification with respect to formal requirements, and of an implementation with respect to a specification, and so provides valuable verification methods in high integrity system development. However, proof development by hand tends to be an erudite, error-prone and seemingly interminable task. Tactics are programs that drive theorem-provers, thus automating proof development and alleviating some of the problems mentioned above. The development of tactics for a particular application domain also extends the domain of application of the theorem-prover. A LCF-tactic is safe in that if it fails to be applicable to a particular conjecture, then it will not produce an incorrect proof. The current construction of tactics from proofs does not yield sufficiently robust tactics. Proofs tend to be specific to the details of a specification and so are not reusable in general, e.g. the same proof may not work when the definition of a conjecture is changed. The major challenges in proof development are deciding which proof rule and instantiations to apply in order to prove a conjecture. Discerning patterns in formal interactive proof development facilitates the construction of robust tactics that can withstand definitional changes in conjectures. Having developed an interactive proof for a conjecture, we develop the necessary abstractions of the proof steps used, to construct a tactic th at can be applicable to other conjectures in that domain. By so doing we encode human expertise used in the proof development, and make proofs robust and thus generally reusable. We apply our theory on the proofs of conjectures involving some set theory operators, and on the proof obligations that arise in the formal development of numerical specifications using the retrenchment method under the IEEE-854 floating-point standard in the PVS theorem-prover/proof-checker

Peace and Reconciliation: Hallmarks for Social Justice in Nigeria

Time after time people of different ethnic extractions in Nigeria have expressed sentiment on deep-rooted grievances exemplified in the abandon property saga, the June 12 annulment, inequitable derivative formula, electoral fraud, poor funding of research institutions, unjust retrenchments, corruption, unlawful retirement from Nigeria Armed Forces and ethnic conflicts. They have displayed the need to either change or improve their societal conditions which may be in form of economic crises, socio-political chaos and upheaval for the better. Their reactions might come in different ways such as mute indifference, silent resignation, vocal utterances and dauntless violence against groups and the leadership. Most of these reactions do not seem productive for a number of reasons: we seem to take the hood for the monk. This explains that we have not tackled the real problem of our society, because we do not seem to labor enough and conscientiously too to discover the roots of people and reconciliation as hallmarks for social justice in Nigeria. The search for the diagnosis and prognosis of the ailment is what I have set out to do in this work through primary and secondary sources of data. The paper identifies the worth and pride of peace and reconciliation play as panacea for cultured people committed to peaceful coexistence, social justice and sustainable Nigerian development

Socio-Cultural and Demographic Issues in E-Business Conflict Resolution: The Nigerian Case

Modern business presents different experiences for different people as well as for different classes in all socio-cultural environments. As e-business creates possible openings for business, it also raises some issues especially when evaluated in the light of current global happenings. While a few of these issues are technically determined, others affect economic, political, cultural and socio-demographic compositions of human society. This paper undertakes a systematic analysis and exploration of the socio-cultural and demographic issues in the environment within which e-business takes place in Nigeria. It considers the emergence of e-business and then raises socio-cultural issues such as mode of production, economic structure, norms/legal/security issues and beliefs as well as demographic issues including size of population, spatial distribution, age and sex composition and components of population dynamics (fertility, mortality, migration) as enhancing and inhibiting factors engendering conflict in e-business promotion. Finally, it proffers solutions to the inherent conflicts arising from these inhibitive tendencies. Keywords: Socio-cultural, demographic, e-business, conflict resolution, globalization, Nigeria

Socio-Cultural and Demographic Issues in E-Business Conflict Resolution: The Nigerian Case

Modern business presents different experiences for different people as well as for different classes in all socio-cultural environments. As e-business creates possible openings for business, it also raises some issues especially when evaluated in the light of current global happenings. While a few of these issues are technically determined, others affect economic, political, cultural and socio-demographic compositions of human society. This paper undertakes a systematic analysis and exploration of the socio-cultural and demographic issues in the environment within which e-business takes place in Nigeria. It considers the emergence of e-business and then raises socio-cultural issues such as mode of production, economic structure, norms/legal/security issues and beliefs as well as demographic issues including size of population, spatial distribution, age and sex composition and components of population dynamics (fertility, mortality, migration) as enhancing and inhibiting factors engendering conflict in e-business promotion. Finally, it proffers solutions to the inherent conflicts arising from these inhibitive tendencies. Keywords: Socio-cultural, demographic, e-business, conflict resolution, globalization, Nigeria