A multi-paradigm language for reactive synthesis

This paper proposes a language for describing reactive synthesis problems that integrates imperative and declarative elements. The semantics is defined in terms of two-player turn-based infinite games with full information. Currently, synthesis tools accept linear temporal logic (LTL) as input, but this description is less structured and does not facilitate the expression of sequential constraints. This motivates the use of a structured programming language to specify synthesis problems. Transition systems and guarded commands serve as imperative constructs, expressed in a syntax based on that of the modeling language Promela. The syntax allows defining which player controls data and control flow, and separating a program into assumptions and guarantees. These notions are necessary for input to game solvers. The integration of imperative and declarative paradigms allows using the paradigm that is most appropriate for expressing each requirement. The declarative part is expressed in the LTL fragment of generalized reactivity(1), which admits efficient synthesis algorithms, extended with past LTL. The implementation translates Promela to input for the Slugs synthesizer and is written in Python. The AMBA AHB bus case study is revisited and synthesized efficiently, identifying the need to reorder binary decision diagrams during strategy construction, in order to prevent the exponential blowup observed in previous work.Comment: In Proceedings SYNT 2015, arXiv:1602.0078

Dense-choice Counter Machines revisited

This paper clarifies the picture about Dense-choice Counter Machines, which have been less studied than (discrete) Counter Machines. We revisit the definition of "Dense Counter Machines" so that it now extends (discrete) Counter Machines, and we provide new undecidability and decidability results. Using the first-order additive mixed theory of reals and integers, we give a logical characterization of the sets of configurations reachable by reversal-bounded Dense-choice Counter Machines

Neopatrimonialism revisited : beyond a catch-all concept

The article provides a critical discussion of the literature on “patrimonialism” and "neopatrimonialism” as far as the use in Development Studies in general or African Studies in particular is concerned. To overcome the catch-all use of the concept the authors present their own definition of “neopatrimonialism” based on Max Weber’s concept of patrimonialism and legal-rational bureaucracy. However, in order to make the concept more useful for comparative empirical research, they argue, it needs a thorough operationalisation (qualitatively and quantitatively) and the creation of possible subtypes which, in combination, might contribute to a theory of neopatrimonial action.Der Artikel unterzieht die beiden Konzepte „Patrimonialismus“ und „Neopatrimonialismus“, wie sie in der entwicklungstheoretischen Literatur und in Afrikastudien Verwendung finden, einer kritischen Analyse. Damit dem Konzept des Neopatrimonialismus mehr als nur eine heuristische Bedeutung zukommen kann, präsentieren die Autoren eine eigene Definition des Begriffs, die sich eng an die Weber’schen Konzepte des Patrimonialismus und der legal-rationalen Bürokratie anlehnt. Darüber hinaus ist auf dieser Grundlage (1) eine sorgfältige (qualitative und/oder quantitative) Operationalisierung des Konzeptes und (2) die Bildung von möglichen Subtypen notwendig. Erst dann kann das Konzept sinnvoll für die vergleichende empirische Forschung eingesetzt und möglicherweise etwas wie eine neopatrimoniale Handlungstheorie entwickelt werden

Cuban Exceptionalism Revisited

The end of Cuban exceptionalism has been much announced since 1989, but a decade and a half later state socialism on the island is still enduring. Transition studies have been criti-cized for focusing on success stories. Exploring the deviant case of Cuba’s “non-transition” from a comparative social science perspective can shed light on the peculiarities of this case and, more importantly, test the general assumptions underlying post-1989 expecta-tions of regime change in Cuba. Theories of path dependence and cumulative causation are particularly helpful when attempting to link Cuban current political exceptionalism with a more long-term historic perspective. Moreover, they suggest that interpretations of Cuba as simply a “belated” case of “third wave” democratization may prove erroneous, even when the health of Fidel Castro finally falters.Cuba, comparative politics, exceptionalism, socialism, transition

Quantum teleportation and Grover's algorithm without the wavefunction

In the same way as the quantum no-cloning theorem and quantum key distribution in two preceding papers, entanglement-assisted quantum teleportation and Grover's search algorithm are generalized by transferring them to an abstract setting, including usual quantum mechanics as a special case. This again shows that a much more general and abstract access to these quantum mechanical features is possible than commonly thought. A non-classical extension of conditional probability and, particularly, a very special type of state-independent conditional probability are used instead of Hilbert spaces and wavefunctions.Comment: 21 pages, including annex, important typo in annex corrected in v2, Found Phys (2017

The 4-particle hydrogen-antihydrogen system revisited: twofold Hamiltonian symmetry and natural atom antihydrogen

Modern ab initio treatments of H-Hbar systems are inconsistent with the logic behind algebraic Hamiltonians H(+-)=H(0)+/-deltaH for charge-symmetrical and charge-asymmetrical 4 unit charge systems like H(2) and HHbar. Since these 2 Hamiltonians are mutually exclusive, only the attractive one can apply for stable natural molecular H(2). A wrong choice leads to problems with antiatom Hbar. In line with earlier results on band and line spectra, we now prove that HL chose the wrong Hamiltonian for H(2). Their theory explains the stability of attractive system H(2) with a repulsive Hamiltonian instead of with the attractive one, representative for charge-asymmetrical system HHbar. A new second order symmetry effect is detected. Repulsive HL Hamiltonian H(+) applies at long range but at the critical distance, attractive charge-inverted Hamiltonian H(-)takes over and leads to bond H(2) but in reality, HHbar, for which we give an analytical proof. Another wrong asymptote choice in the past also applies for atomic antihydrogen Hbar, which has hidden the Mexican hat potential for natural hydrogen. This generic solution removes most problems, physicists and chemists experience with atomic Hbar and molecular HHbar, including the problem with antimatter in the Universe.Comment: at the instituional UGent archive, 37 pag, 10 fig, tabb, version as submitted, abstract shortene