Contracts for Interacting Two-Party Systems

This article deals with the interrelation of deontic operators in contracts -- an aspect often neglected when considering only one of the involved parties. On top of an automata-based semantics we formalise the onuses that obligations, permissions and prohibitions on one party impose on the other. Such formalisation allows for a clean notion of contract strictness and a derived notion of contract conflict that is enriched with issues arising from party interdependence.Comment: In Proceedings FLACOS 2012, arXiv:1209.169

Counterexamples to simulation in non-deterministic call-by-need lambda-calculi with letrec

This note shows that in non-deterministic extended lambda calculi with letrec, the tool of applicative (bi)simulation is in general not usable for contextual equivalence, by giving a counterexample adapted from data flow analysis. It also shown that there is a flaw in a lemma and a theorem concerning finite simulation in a conference paper by the first two authors

Wages, labor or prices: How do firms react to shocks? National Bank of Belgium Working Paper, No. 193, July 2010

Survey results in 15 European countries for almost 15,000 firms reveal that Belgian firms react more than the average European firm to adverse shocks by reducing permanent and temporary employment. On the basis of a firm-level analysis, this paper confirms that the different reaction to shocks is significant and investigates what factors explain this difference. Although the explanatory value of the variables is limited, most of the explanatory power of the model being associated with the dummy variables coding for firm size, sector and country, the variables investigated provide valuable information. The importance of wage bargaining above the firm level, the automatic system of index-linking wages to past inflation, the limited use of flexible pay, the high share of low-skilled blue-collar workers, the labor intensive production process as well as the less stringent legislation with respect to the protection against dismissal are at the basis of the stronger employment reaction of Belgian firms. On the contrary, employment is safeguarded by the presence of many small firms and a wage cushion

Why Hasn’t Economic Growth Killed Religion?

Economic growth has not led to a decline in religion despite past predictions that it would. I use a formal model of religious competition to show how economic growth produces counteracting effects on religious participation in an open religious market, while economic growth will have little effect in a religious market that is already secularized due to religious regulations. Theories predicting the decline of religion due to rising opportunity costs of religious demand and supply ignore countervailing influences.Religion; Hotelling, entry deterrence

The role of parenting styles on behavior problem profiles of adolescents

Parental behavior is one of the most influential factors on the development of adolescent externalizing and internalizing behavior problems. These behavioral problems are closely related and often co-occur. The objectives of this work were: (i) to identify adolescents profiles according to their behavior problems; (ii) to explore individual, family, and social characteristics associated with these profiles; and (iii) to analyze the potential role of parenting styles in belonging to adolescents’ profiles. A total of 449 Spanish adolescents (223 from families declared at-risk and enrolled in Child Welfare Services and 226 from families from the general population) participated in this study. The analyses revealed three profiles of adolescents based on external and internal behavior problems (adjusted, external maladjustment, and internal maladjustment). Parenting styles explained the adolescents’ belonging to different profiles, in which the indulgent style was the most favorable in general terms. The distinctive role of parenting styles on two types of maladjustment profiles was confirmed. The relationship between parenting styles and adolescent adjustment is a key component that should be included in interventions according to adolescents’ behavior problem profiles. Furthermore, the results shed light on the need that family interventions are complemented with individualized interventions with adolescents that accumulate stressful life events.Ministerio de Economía y Competitividad EDU2013-41441-

The effect of boundary adaptivity on hexagonal ordering and bistability in circularly confined quasi hard discs

The behaviour of materials under spatial confinement is sensitively dependent on the nature of the confining boundaries. In two dimensions, confinement within a hard circular boundary inhibits the hexagonal ordering observed in bulk systems at high density. Using colloidal experiments and Monte Carlo simulations, we investigate two model systems of quasi hard discs under circularly symmetric confinement. The first system employs an adaptive circular boundary, defined experimentally using holographic optical tweezers. We show that deformation of this boundary allows, and indeed is required for, hexagonal ordering in the confined system. The second system employs a circularly symmetric optical potential to confine particles without a physical boundary. We show that, in the absence of a curved wall, near perfect hexagonal ordering is possible. We propose that the degree to which hexagonal ordering is suppressed by a curved boundary is determined by the `strictness' of that wall.Comment: 10 pages, 8 figure

The Sigma-Semantics: A Comprehensive Semantics for Functional Programs

A comprehensive semantics for functional programs is presented, which generalizes the well-known call-by-value and call-by-name semantics. By permitting a separate choice between call-by value and call-by-name for every argument position of every function and parameterizing the semantics by this choice we abstract from the parameter-passing mechanism. Thus common and distinguishing features of all instances of the sigma-semantics, especially call-by-value and call-by-name semantics, are highlighted. Furthermore, a property can be validated for all instances of the sigma-semantics by a single proof. This is employed for proving the equivalence of the given denotational (fixed-point based) and two operational (reduction based) definitions of the sigma-semantics. We present and apply means for very simple proofs of equivalence with the denotational sigma-semantics for a large class of reduction-based sigma-semantics. Our basis are simple first-order constructor-based functional programs with patterns